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I
Highlights,
Oand Needs
The focus in this volume is solely on condensed-
matter physics, which is the foundation of a significant
portion of the broader field of materials science, and
the dividing line between the two fields is not always a
sharp one. However, we are not surveying materials
science nor the considerable impact of condensed-
matter physics on technology. The interface between
physics and technology will receive fuller treatment in
another volume in this survey.
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HIGHLIGHTS, OPPOR TUNI TIES, AND NEEDS 3
CONDENSED-MATTER PHYSICS AND ITS IMPORTANCE
Condensed-matter physics is the fundamental science of solids and
liquids, states of matter in which the constituent atoms are sufficiently
close together that each atom interacts simultaneously with many
neighbors. It also deals with states intermediate between solid and
liquid (e.g., liquid crystals, glasses, and gels), with dense gases and
plasmas, and with special quantum states (superfluids) that exist only
at low temperatures. All these states constitute what are called the
condensed states of matter.
Condensed-matter physics is important for two reasons. The first is
that it provides the quantum-mechanical foundation of the classical
sciences of mechanics, hydrodynamics, thermodynamics, electronics,
optics, metallurgy, and solid-state chemistry. The second is the mas-
sive contributions that it provides to high technology. It has been the
source of such extraordinary technological innovations as the transis-
tor, superconducting magnets, solid-state lasers, and highly sensitive
detectors of radiant energy. It thereby directly affects the technologies
by which people communicate, compute, and use energy and has had
a profound impact on nonnuclear military technology.
At the fundamental level, research in condensed-matter physics is
driven by the desire to understand both the manner in which the
building blocks of condensed matter-electrons and nuclei, atoms and
molecules combine coherently in enormous numbers (~1024/cm3) to
form the world that is visible to the naked eye, and much of the world
that is not, and the properties of the systems thus formed. It is in the
fact that condensed-matter physics is the physics of systems with an
enormous number of degrees of freedom that the intellectual challenges
that it presents are found. A high degree of creativity is required to find
conceptually, mathematically, and experimentally tractable ways of
extracting the essential features of such systems, where exact treat-
ment is an impossible task.
Condensed-matter physics is intellectually stimulating also because
of the discoveries of fundamentally new phenomena and states of
matter, the development of new concepts, and the opening up of new
subfields that have occurred continuously throughout its 60-year
history. It is the field in which advances in quantum and other theories
most directly confront experiment and has repeatedly served as a
source or testing ground for new conceptual ways of viewing complex
systems. In fact, condensed-matter physics is unique among the
various subfields of physics in the frequency with which it feeds its
fundamental ideas into other areas of science. Thus, advances in such
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4 HIGHLIGHTS, OPPORTUNI TIES, AND NEEDS
subareas of condensed-matter physics as many-body problems, critical
phenomena, broken symmetry, and defects have had a major impact on
nuclear physics, elementary-particle physics, astrophysics, molecular
physics, and chemistry. These advances continue and over the promise
of equally fundamental discoveries in the next decade.
At the same time, condensed-matter physics excites interest because
of the well-founded expectations for applications of discoveries in it.
Of all the branches of physics, condensed matter has the greatest
impact on our daily lives through the technological developments to
which it gives rise. Such familiar devices as the transistor, which has
led to the miniaturization of a variety of electronic appliances; the
semiconductor chip, which has made possible all the myriad aspects of
the computer; magnetic tapes used in recording of all kinds; plastics for
everything from kitchen utensils to automobile bodies; catalytic con-
verters to reduce automobile emissions; composite materials used in
fan jets and modern tennis rackets; and NMR tomography are but a few
of the practical consequences of research in condensed-matter physics.
A whole new technology, optical communications, is being developed
at this time from research in condensed-matter physics, optics, and the
chemistry of optical fibers.
These examples serve to illustrate the intimate connection between
fundamental science and the development of basic new technology in
condensed-matter physics. In both universities and industry they are
carried out by people with the same research training, who use the
same physics concepts and the same advanced instrumentation. Be-
cause fundamental science in condensed-matter physics is so deeply
involved with technological innovation, it has a strong natural bond
with industry. This is the main reason why condensed-matter physics
has been so successful in leading industrial innovation.
Indeed, the full extent to which the consequences of research in
condensed-matter physics play a role in the quality of our everyday
lives, and in meeting national needs, is far greater than any such listing
can indicate. In order to show this explicitly we have constructed the
matrix displayed in Table 1, the first column of which lists the subareas
of condensed-matter physics, and the first row the major areas of
human and technological activity that are of national interest. The
elements of the matrix are filled in with a solid circle, indicating a
critical connection between the corresponding subarea of condensed-
matter physics and the area of application; a half-filled circle, indicating
an important or emerging connection; an open circle, denoting the
possibility of a connection; or a blank, implying that the connection is
not known. In Appendix A this matrix is repeated, but with qualitative
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6 HIGHLIGHTS, OPPORTUNITIES, AND NEEDS
comments concerning the connections replacing the various circles.
This table makes the point graphically that condensed-matter physics
plays an indispensable role in the maintenance of the quality of our
daily life and in providing for national security.
DISCOVERY
The 1 950s saw such achievements as the rapid development of
semiconductor technology after the discovery of the transistor; the rise
of many-body theory (the application of the methods of quantum field
theory to large and complex systems) as a field of theoretical physics,
and its crowning achievement, the solution of the 50-year-old problem
of superconductivity; the heyday of magnetic resonance methods in
physics; and the elucidation of the Fermi surfaces of metals. The 1960s
saw the discovery of high critical fields and superconducting magnets,
as well as of the Josephson erect and other electron tunneling methods
and devices; the construction of the first working lasers and further
giant strides in laser physics; the initial explanation of the ancient
problem of the resistance minimum by Kondo and the opening up of a
whole new physics of similar Fermi-surface effects in metals such as
the x-ray edge; the development of pseudopotential and density
functional methods, among others, that have made electronic structure
calculations almost routine; and the initial development of high-energy
probe methods for the study of electronic structure such as ultraviolet
photoelectron spectroscopy (UPS) and x-ray photoelectron spectros-
copy (XPS).
From time to time, there have been those who have predicted the
end of this era of discovery. Remarkably, the subject continues to
produce surprises. In what follows we present a selection of some of
the most interesting advances in condensed-matter physics that oc-
curred in the 1970s and early 1980s.
Artificially Structured Materials
One area of condensed-matter physics that has progressed remark-
ably in the past decade is that of artificially structured materials-
materials that have been structured either during or after growth to
have dimensions or properties that do not occur naturally.
The most important techniques for the creation of such materials are
molecular-beam epitaxy (MBE), the molecule-by-molecule deposition
of material of the desired composition from a molecular beam' and
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HIGHLIGHTS, OPPORTUNITIES, AND NEEDS 7
metallo-organic chemical vapor deposition (MOCVD). These are prime
examples of technological breakthroughs, used primarily to make
semiconductor lasers and other devices, feeding back to fundamental
physics. One can fabricate artificial periodic superlattices consisting of
alternating layers of different semiconductors, different metals, or
semiconductors and metals, and one can also create artificial, purely
two-dimensional electron gases. The latter have unique and important
properties, e.g., extremely high electron mobilities, which cannot be
provided by metal-oxide-semiconductor (MOS) inversion layers. The
new physical phenomena to which the resulting structures have given
rise include the quantized Hall effect and the fractionally quantized
Hall effect. It has also been possible to grow metallic superlattices
in which the electronic mean free path is appreciably longer than
the period of the superlattices (the sum of the thicknesses of the
two alternating metal layers). It is found that it is possible to induce
new lattice structures rather easily in such superlattices. Metal/insu-
lator superlattices are ideal systems for the study of dimensional
effects in metals, e.g., the crossover from two- to three-dimensional
superconductivity in Nb/Ge superlattices as the Ge thickness is de-
creased.
The Quantized Hall Eject
Modern technology has made possible unique, purely two-
dimensional electron gases (in the sense that only one quantum state is
excited in the direction perpendicular to the plane of the gas, so that
electronic motion in it is strictly confined to that plane). These systems
show exciting properties and are a new laboratory for the study of
fundamental physics. The most remarkable property of such systems is
undoubtedly the quantized Hall eject. At low temperature and high
perpendicular magnetic field, the electron states are split into so-called
Landau or cyclotron energy levels. It is found that when the Fermi
level is between two such levels one sees an almost perfectly flat
plateau or constant value of the Hall conductance, the conductance
perpendicular to the electric and magnetic fields, as well as zero
parallel conductance. These plateaus are found to be quantized in units
of e21h = 1/25,812.8 ohm-~. The precision of this result, at least one
part in a hundred million, has led to improvement in the measurement
of this fundamental constant and to a new portable resistance standard.
More recently, quantization of the Hall conductance in simple fractions
like 1/3, 2/5, and 2/7 of e21h has been seen, and an explanation of this
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8 HIGHLIGHTS. OPPORTUNITIES, AND NEEDS
effect has been proposed, and widely accepted, that involves a
completely new and unexpected ordered state of matter. In this state
one proposes that a new type of elementary excitation with fractional
electronic charge plays a major role.
Ejects of Reduced Dimensionality
For many years condensed-matter theorists studied one- and two-
dimensional models of solids because it was often possible to obtain
exact results there where the corresponding, physical, three-dimen-
sional models were intractable. The existence of such exact solutions
in low-dimensional systems has prompted experimentalists to search,
successfully, for physical systems whose physical properties agree well
with those of one- and two-dimensional theoretical models. These
include quasi-one-dimensional magnetic systems composed of chains
of magnetic atoms, separated from each other by nonmagnetic atoms,
and quasi-two-dimensional systems realized by layered compounds,
such as graphite intercalation compounds, in which atomic layers are
widely separated and weakly interacting.
Other examples have arisen either out of technological discoveries or
from the synthesis of interesting new materials. The inversion layers
used in the quantized Hall effects are an example of reduced dimen-
sionality systems important in technology, an example that has been
vital to the physics of disordered systems as well. Another is the
development of methods for studying adsorbed layers on surfaces that
undergo phase transitions of typically two-dimensional type. A third is
the discovery of methods for making freely suspended layers of a liquid
crystal one or a few molecules thick.
New materials showing metallic properties in only one or two
dimensions have been synthesized, for instance the transition-metal
dichalcogenides, which can be cleaved to produce single layers or
intercalated with large molecules that separate the layers by large
distances, and a number of organic one-dimensional chain metals such
as polyacetylene. These various developments have encouraged ex-
perimentalists and theorists to think of dimensionality as a new free
parameter.
Charge-Density Waves
Among phenomena that are most clearly demonstrated in low-
dimensionality systems are charge (or in some cases spin) density
waves. A few isolated cases in which the structure of a solid was
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HIGHLIGHTS, OPPORTUNITIES, AND NEEDS 9
modulated periodically had been known for decades, but it was not
until modern low-dimensionality materials became available, such as
the dichalcogenides and trichalcogenides of Nb and other transition
metals, and some organic metals, such as polyacetylene and tetra-
thiafulvalene-tetracyanoquinodimethane (TTF-TCNQj, that the phe-
nomenon could be studied in general. Theory has predicted for many
years that such materials should show density waves especially easily.
In such materials the structure contains two periods that may be
incommensurate, hence giving an overall nonperiodic structure. A
particularly important possibility is the sliding of such an incommen-
surate wave through the parent lattice, a new phenomenon illustrating
in a clean microscopic model the age-old effects of sliding and sticking
friction. The materials that display these ejects, e.g., NbSe3 and TaS3,
are remarkable quantum systems with the richness of superconductiv-
ity and should be excellent for studying various aspects of macroscopic
quantum phenomena. Other interesting phenomena relate to defects in
these waves, which have strange topological properties, fractional
charge per unit area, and, in the case of polyacetylene, strange spin and
charge properties. This subject continues to be actively discussed, not
only because of its scientific interest but also because of its possible
technical interest.
Disorder
It is only within the past decade that physicists have begun to focus
on the problems intrinsic to disordered states of matter such as random
alloys, glass, and gels. Historically they had dealt with such systems-
often effectively by trying to average out the disorder in the most
efficient possible way, to produce an '`effective medium." Now they
have begun to look for intrinsic properties of disordered materials. The
most striking of these is localization, the tendency to form quantum
states that cannot move except with the help of thermal energy.
Experimentally, the study of localization is much clarified by using a
two-dimensional geometry, in which one often sees a unique nonclas-
sical behavior of the electronic conductivity, and by technical ad-
vances in microfabrication, which allow the study of effectively
one-dimensional wires and of tiny loops that show strange conductivity
-oscillations in a magnetic field. A second disordered material of
technical importance is glass; the glass transition and the high-
temperature annealing properties of glass remain almost completely
mysterious, but a whole new physics has grown up around a new entity
recently discovered in the low-temperature behavior of glass, the
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10 HIGHLIGHTS, OPPORTUNITIES, AND NEEDS
so-called tunneling centers. The structure of glass is also a great
mystery; the computer may help in deciphering it, but in fact we know
so little that we do not yet even believe we can program a computer to
make a viable model of glass.
Mixed Valence and Heavy Fermions
It is not uncommon, the chemists have found, for the same chemical
element to exhibit two valences in the same compound as, for
example, magnetite, which contains both ferrous and ferric iron at
different atomic positions. On the other hand, metals such as nickel do
not necessarily have a fixed valence, as the electrons move freely
through the lattice. The rare-earth metals, however, normally have a
fixed valence for the inner f electrons, which can be identified because
they show magnetic properties identical to those of ions in an insulating
salt. It now appears that there is a large class of compounds based on
the rare-earth atoms Ce, Sm. Eu, Tm, Yb, and now the actinide
element U. that are intermediate between these two cases in an unusual
way. Some types of measurements one-electron probes, x-ray
edges show both valences simultaneously developed on the same
atom. Other types of measurement, such as those of low-temperature
magnetism or conductivity, show a fixed valence, sometimes interme-
diate and sometimes not. It appears that electrons are quantum
mechanically tunneling rather slowly in and out of the f shells, with
very exotic results, such as electron bands with effective electron
masses as large as 1000 times a normal electron mass, which nonethe-
less exhibit superconductivity at very low temperatures. Present
speculation is that these superconductors are of a totally new type,
and are analogous to superfluid 3He. The valence fluctuations in other
materials lead to a number of other fascinating effects: metal/insulator
transitions, magnetic/nonmagnetic transitions, soft (highly compress-
ible) lattices, and transitions into exotic magnetic ground states. A full
explanation of these phenomena might have far-reaching consequences
for our understanding of magnetism and bonding in solids.
The Superfluid Phases of 3He
A high point in research in condensed-matter physics of the last
decade was the discovery that 3He is a superfluid (i.e., can flow without
resistance through narrow channels) at temperatures below 3 mK. This
is the first, and only, new superfluid to be discovered since the
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HIGHLIGHTS, OPPORTUNITIES, AND NEEDS 11
superfluidity of 4He was established in 1937. The properties of 3He are
very different from those of 4He because 4He obeys the quantum-
mechanical laws of Bose statistics, whereas 3He obeys Fermi statistics,
the same as electrons. At the same time, superfluid 3He displays a rich
variety of physical properties in addition to those possessed by the
previously known superfluids. This is because the interaction between
pairs of helium atoms that is responsible for the superfluidity of 3He is
qualitatively different from the interaction between pairs of electrons
responsible for the superconductivity of all the currently known
superconductors. In particular the superfluid is locally anisotropic,
acting as though it was made up of molecules with internal rotational
motions about a specific direction.
Several major advances in condensed-matter physics were fueled
primarily by new theoretical concepts. Descriptions of two of them
follow.
The Renormalization Group Methods
These techniques are useful in dealing with physical phenomena in
which there exist fluctuations that occur simultaneously over a wide
range of different length, energy, or time scales. The method proceeds
by stages, in which one successively discards the shortest-wavelength
fluctuations until a few macroscopic degrees of freedom remain. The
effects of the short-wavelength fluctuations are taken into account
approximately at each stage by a renormc~lizc~tion, i.e., change in
magnitude, of the interactions among the remaining long-wavelength
modes. These techniques were developed initially in particle physics
but came into their own in the theory of phase transitions, the branch
of condensed-matter physics that deals with changes of state, such as
the melting and freezing of solids and liquids and the magnetization of
ferromagnets. Their use has provided a theoretical understanding of
empirical relations among different properties near the phase transition
or critical point of a given system and has made it possible to predict
critical properties with a high degree of accuracy. These predictions
have been confirmed by a wide variety of subsequent experiments. The
renormalization group techniques have found applications in such
diverse areas of condensed-matter physics as disordered electronic
systems, impurity problems, disordered magnetic materials called spin
glasses, nonlinear dynamical systems, long polymer chains, and per-
colation through macroscopically inhomogeneous systems such as
porous rocks.
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26 HIGHLIGHTS, OPPORTUNI TIES, AND NEEDS
research in condensed-matter physics more rewarding but also more
expensive. A supercomputer, such as the CRAY-XMP, costs around
$10 million, and at present only three universities in the United States
have one. A computer of the type of a VAX 11-780 costs in the vicinity
of $200,000. Even if research groups do not own their own computer,
the cost of purchasing computer time can be a significant portion of the
cost of present-day research. The future health of the field requires that
this clearly identified need for computers be accommodated.
As computing needs are diverse requiring both increased capacity
and capability they cannot all be filled by the medium-sized main-
frame computers found on most research campuses. There is a specific
need in theoretical work for advanced computing capabilities. Some of
these can often be met by adding a fast processor to a conventional
computer at a cost of about $40O,OOO. Almost an order of magnitude or
more additional computing power can be provided by modern
supercomputers and, in some fraction of cases, the provision of time on
such machines if not the machines themselves for condensed-
matter research is essential. The future funding patterns must accom-
modate the growing demands for computer use. To this end,
We recommend that sufficient new monies be appropriated to allow the several
federal agencies supporting condensed-matter research to identify a continuing
fraction of the total budget to be devoted to the special computing needs of
condensed-matter research. The assignment to computing of 10 percent or
more of the total present budget would appear well justified. The funds so
assigned could be used for the purchase of computer time or for the purchase
and maintenance of dedicated equipment.
In view of rapid changes in computer technology and patterns of use in
the physics community, this fraction should be reconsidered after the
next few years of experience. The scientific community and the federal
funding agencies should work together to promote more effective use
of major computer resources through networking, standardization, and
the establishment of user assistance groups.
FUNDING
The chances of realizing the research opportunities that the coming
decade offers will be significantly enhanced by an increase in the
number of individuals carrying out this research, an increase in the
level of support that they receive, and the provision of the increasingly
more sophisticated, and the increasingly more costly, equipment that
they will need in their work.
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HIGHLIGHTS. OPPORTUNITIES, AND NEEDS 27
The costs of conducting a modern research program include the
maintenance of equipment, the operating or running costs, and the
salaries and benefits for personnel. These costs will increase more
rapidly than inflation because of the increased sophistication of the
required equipment and the expected increases in tuition for graduate
students.
The national investment required for the adequate support of basic
research in condensed-matter physics by individual researchers, how-
ever, is not great, even though the return on the investment is large.
There is heartening evidence in the current federal budget, through its
approximately 20 percent increase in support for basic science over the
level for last year, that this is recognized. However, more still needs to
be done to capitalize on the opportunities that exist.
We estimate that implementing the preceding recommendations will require an
increase in funding for research in condensed-matter physics at a steady annual
expansion rate of approximately 20 percent in constant dollars for an additional
3 years. We strongly recommend that this increase take place.
The special claim of condensed-matter physics for research support
from federal and industrial sources lies in its record of converting deep
science into benign and sophisticated industrial technology on a time
scale that is often no more than 5 to 10 years. This process is still
vigorously under way with such notable new scientific discoveries as
the quantized Hall eject, valence fluctuations, heavy electron-mass
metals, electron localization due to disorder, artificially structured
materials, conducting polymers, chaotic phenomena in solids and
liquids, and solitary wave phenomena in solids. If the resources
become available to carry out the research necessary to exploit these
new discoveries, the impact An industrial technology will be even
greater than what has gone before.
Support for National Facilities
Some of the national facilities are comparatively new; others have
been in existence for many years. Because of their importance for the
nation's scientific effort, the facilities that continue to maintain a high
level of scientific excellence should be adequately supported. Planning
for new facilities to meet the needs of new areas of condensed-matter
physics that are now developing must begin in the near future.
The needs of the neutron and synchrotron facilities have been
subjected to detailed scrutiny recently by several panels sponsored by
the NSF and the Department of Energy (DOE). The most recent of
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28 HIGHfIGHTS,OPPORTUNITIES,AND NEEDS
these studies* was prepared while this report was being written. We
will have occasion to refer to it in what follows.
NEUTRON FACILITIES
The existing high-flux reactors, the cornerstones of the U.S. neu-
tron-scatter~ng program, are underfunded and understaffed. Relative to
their Western European counterparts they are falling seriously behind
in instrumentation. Therefore,
We recommend that a concerted and coordinated effort should be undertaken
to expand the effectiveness of our high-performance reactors by adding new,
diversified instruments along with personnel necessary to design, build, and
utilize them in the user mode. We estimate that at least ten new instruments are
needed, requiring an increase in annual operating costs of $2 million to $3
million for manpower needed for their design and use. About $20 million to $30
million is required for building such instruments, to be spent over 5 to 7 years.
Instrumentation plans beyond the level projected above may be warranted but
should be justified by demonstrated user needs.
Note that this estimate does not attempt to address the somewhat
different needs of the chemistry and biology communities. A 1984
Panel on Neutron Scattering, considering the total scientific commu-
nity, estimated a need for ~30 new instruments."
Spallation sources provide new opportunities to expand the power of
the neutron as a probe of condensed matter. The United States
currently has two pulsed spallation sources. The Los Alamos Neutron
Scattering Center (LANSCE) facility at the Los Alamo s National
Laboratory is compromised currently by the pulse structure of the
LAMPF proton beam that supplies it. This situation will be corrected
by the addition of a proton storage ring (PSR) scheduled for completion
in 1986. It is also restricted by the small experimental hall. The Intense
Pulsed Neutron Source (IPNS) at the Argonne National Laboratory,
with an active otltside-user community, an experienced stab, and an
adequate experimental hall, is the highest-performance source in
operation at present.
* Major Facilities for Materials Research and Related Disciplines (National Academy
Press, Washington, D.C., 1984). This will be referred to below as the report of the
Seitz-Eastman committee.
~ Current Status of Neutron-Scattering Research and Facilities in the United States
(National Academy Press, Washington, D.C., 1984).
OCR for page 29
HIGHLIGHTS, OPPORTUNITIES, AND NEEDS 29
We therefore recommend that funds be appropriated to enlarge the LANSCE
instrument hall (a $15 million construction project has been proposed) and
operation of IPNS be continued until the latter's ongoing activities can be
accommodated by a more powerful and cost-effective LANSCE, provided this
can be budgeted without jeopardizing the necessary rejuvenation of the
high-performance reactors.
Very recently Argonne has proposed the upgrade of IPNS by the
replacement of the existing accelerator with one of new design (fixed
field, alternating gradient) with a sevenfold increase in proton current.
If this design is shown to be practical and cost-effective relative to
LANSCE, it will be necessary to reconsider our spallation-source
priorities in the light of the existing investments.
There are no comprehensive plans at present concerning the status
of our neutron capabilities for the 1990s. Given the uncertainties in the
lifetimes of existing facilities and the time necessary for the design and
construction of new facilities, it seems advisable for the neutron-
scattering community to initiate discussions immediately leading to
such a plan. The feasibility and desirability of both steady-state and
pulsed sources should be studied. The possibility of establishing such
a facility through international cooperation should also be fully ex-
plored.
We therefore recommend that supplemental funds be made available to
interested qualified institutions to investigate various options for an advanced
neutron source. These studies should be done in parallel and in consultation
with a panel of outside users charged with devising a plan that will ensure that
our neutron-scattering needs will be met in the l990s and beyond.
SYNCHROTRON RADIATION SOURCES RECOMMENDATIONS
Synchrotron radiation has had a broad impact on studies of both the
structural and electronic properties of condensed matter. This is due to
its unique high brightness, wide tunability, high polarization, and
narrow angular divergence (and, in some instances, time structure).
These properties are similar to those of laser sources, but the wave-
length range of synchrotron radiation extends from that of the shortest
known laser wavelength throughout the ultraviolet, soft-x-ray, and
hard-x-ray regions.
It is recommended that the current new generation of synchrotron facilities be
completed as soon as possible since their high brightness will serve the
short-term needs of the next 3 to 5 years.
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30 HIGHLIGHTS, OPPORTUNITIES, AND NEEDS
The main scientific emphasis of these short-term objectives should be
in the following areas: (i) Current beam-line instrumentation should be
refined in order to achieve higher resolution of photon monochromators
in the conventional VUV (0-100 eV) and x-ray (4-15 keV) ranges. This
will allow new types of studies to be made of electronic and structural
phenomena in conventional solids as well as in low-dimensional sys-
tems such as surfaces, polymers, and liquid crystals. (ii) Novel new
instrumentation should be developed for soft x rays in the 100-4000 eV
range that uses combinations of conventional diffraction-grating tech-
nology with new synthetic materials such as multilayer mirrors and
other x-ray optical elements. This would allow high-resolution studies
of the shallow core-level spectra of all elements. In addition both
extended-x-ray absorption fine-structure (EXAFS) and high-resolution
near-edge studies could be performed using K or L edges of elements
with an atomic number smaller than that of xenon. In order to exploit
the potential of insertion devices in the x-ray region it is important that
the design allow first harmonic undulator radiation at energies up to
~20 keV.
A commitment should begin immediately toward the next generation
of high-brightness synchrotron facilities using insertion devices. This
should be a two-step approach.
New undulator and wiggler devices should be constructed on existing stor-
age rings so that insertion-device technology will move ahead rapidly and be
ready for possible new rings. New optical devices should be developed to
match insertion device sources; this should be done in parallel with the
development of new sources, since higher resolution and wider tunability
cannot be achieved simply by attachment of existing beam lines to new
sources.
As a second priority, planning should begin immediately leading to proposals
for a next-generation, possibly all-insertion device machine. Ideally, this
machine should be completed in the early l990s, since projected user demand
will saturate then-existing facilities by that time. The design parameters, such
as electron energy and physical size, should be determined by scientific
considerations, but the three areas of spectroscopy, scattering, and micros-
copy should be accommodated. The 6-GeV machine recommended by the
Seitz-Eastman committee appears to meet these needs. The overall costs of
such a next-generation synchrotron source are in the range of $160 million, and
construction could take place over a period of 6-7 years. Firm decisions on
when to build such a machine should be made on the basis of new scientific
opportunities, user demand, and ongoing experience with the undulator and
wiggler facilities discussed above.
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HIGHLIGHTS, OPPORTUNITIES, AND NEEDS 31
HIGH-MAGNETIC-FIELD FACILITIES RECOMMENDATIONS
Laboratories for the production of high magnetic fields (>15 T.
where 1 T_ 104 Oe) and their utilization in condensed-matter research
exist in France, Holland, Belgium, Japan, Poland, the Soviet Union,
and the United States. The National Magnet Laboratory at the
Massachusetts Institute of Technology is the only major user facility
for high-field research in the United States. A wide variety of steady-
field magnets exist there and are categorized by their peak fields, bore
sizes, and homogeneity. The largest field currently available there is 29
T. in a 3.3-cm-bore hybrid configuration.
Magnetic fields above 30 T are economically feasible only in pulsed
operation. Nondestructive, repetitive pulsed fields in the range 40 T c
H c 60 T are now available in Holland, Japan, and the Soviet Union.
A 75-T configuration will soon be operating in Osaka, Japan. A
high-magnetic-field facility has just been completed at the Institute for
Solid State Physics (ISSP) in Tokyo, Japan, at a cost of about $10
million. It can produce a variety of nondestructive pulsed fields (c50
T); it can produce fields of 50-100 T by plasma compression that may
be nondestructive; and it can produce a 100-500 T implosion-generated
field that is totally destructive of the sample. The ISSP group has been
generating fields of 100 T for several years, which have been used in
studies of cyclotron resonance and various other phenomena in semi-
conductors. No comparable facilities are available in the United States,
although much of the seminal technology was developed in this country.
The availability of high magnetic fields has yielded such experimen-
tal results as the discovery of the fractionally quantized Hall effect.
More generally, high-field magnets expand the phase diagram of a solid
by adding a new variable, the magnetic field, to the usual variables,
pressure and temperature, thereby increasing our knowledge of prop-
erties of solids under extreme conditions. For these reasons, and the
paucity of high-field magnets in the United States,
We recommend that new money should be made available to enable greater
emphasis to be placed on the generation of pulsed high magnetic fields at the
National Magnet Laboratory and/or at a new site elsewhere in the United
States. The cost of duplicating the high-magnetic-field facility in Osaka is
estimated to be $1 million to $2 million.
ELECTRON-MICROSCOPE FACILITIES RECOMMENDATIONS
The country's electron-microscope facilities provide a reservoir of
talent and expertise necessary to generate the innovative instrumenta
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32 HIGHLIGHTS, OPPORTUNITIES, AND NEEDS
lion crucial for promoting the growth of the power and subtlety of
electron-microscopic investigations in the coming decade. There ap-
pear to be four major areas in which advanced instrumental initiatives
could have a major impact on the development of the field during this
period: (1) development of ultrahigh-vacuum sample environments for
surface studies; (2) development of efficient instrumental accessories
for microanalytical techniques such as electron energy loss spectros-
copy; (3) development of low-temperature specimen stages and spec-
imen preparation techniques necessary for systematically attacking
questions about the structures of large biological molecules and of
many others that are of interest to condensed-matter physics; and (4)
development of computerized data collection and analysis. It is esti-
mated that the cost of the major capital equipment required for im-
plementing these instrumental initiatives would average $1 million for
each, spread out over a period of 2 years, for a total of $4 million. The
increase in the operating budgets of the institutions participating in
these initiatives is estimated to be $4 million, to be achieved over a
period of 3-4 years. Our recommendation in this area is as follows:
Advanced instrumentation initiatives in the four areas of electron microscopy
cited above should be established in response to competitive proposals from
interested institutions. If necessary, the federal funding agencies should
stimulate the submission of such proposals.
GENERAL RECOMMENDATIONS CONCERNING NATIONAL
FACILITIES
There are two broad categories of users of national facilities.
Committed users are those whose research programs are built nearly
exclusively around the use of these facilities and include the scientific
staff of the facilities. By contrast, occasional users have research
programs based on other techniques, usually at their home laborato-
ries, but whose research is increased in scope by the power of these
other specialized techniques. The long-term vitality and future growth
of national facilities depend crucially on a broad base of these
occasional users who have neither the time nor the financial resources
to become expert in these techniques but who furnish nonetheless a
wealth of novel materials and ideas for experiments. In order to aid the
integration of these occasional users into the activities of the facilities,
We recommend that special funding be set aside for the purpose of accommo-
dating occasional users at the national facilities. This money would help
finance travel and living expenses, particularly for university users, and
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HIGHLIGHTS, OPPORTUNITIES, AND NEEDS 33
provide an increase in the in-house support staff. This program should be
formulated by the individual facilities in consultation with university and
industrial collaborators and funded on the basis of separate proposals from
these facilities. We estimate that a significant trial program would require $4
million to $6 million per year over a 3-4 year period.
Recently established national facilities (e.g., those dedicated to
research employing synchrotron radiation or high-resolution electron
microscopes) have been developed as user facilities or as DOE Centers
for Collaborative Research. The independent peer review of the
experiments approved to be done improves the quality and nature of
the research at these facilities. At the same time, the ability to respond
to rapidly emerging scientific opportunities and the timely development
of new experimental techniques requires that a certain fraction (per-
haps 30 percent) of the available time be allocated at the discretion of
the in-house staff. Therefore,
We recommend that in the future it is desirable that national facilities should
operate in the user mode in which the majority of experimental time is
allocated by independent peer review.
There are at least two modes in which this peer review may operate:
review of experiment-by-experiment proposals by occasional users and
peer review of proposals for participating research teams (PRTs) that
undertake to construct, maintain, and carry out research programs
using instruments on a shared basis with non-PRT members.
Finally, it is our strongly held view that the needs of the individual
researcher, which have been outlined above in the section on Support
for Individual Researchers, are so great at this time that the highest
priority for the use of new monies for the support of condensed-matter
physics is in meeting those needs and for the upgrading of the existing
national facilities that is necessary for the achievement of their full
potential. When this has been accomplished, the construction of the
new national facilities should begin.
University-Industry-Government Relations
One of the primary strengths of condensed-matter physics is that
forefront research of the highest quality is carried out at industrial
laboratories as well as at universities and government laboratories.
This is due to the fact that condensed-matter physics is closest to
applications in technology of all the subfields of physics. It argues for
a strong coupling between universities and national laboratories, where
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34 HIGHLIGHTS, OPPORTUNI TIES, AND NEEDS
most of the basic research in condensed-matter physics is done? and
industry, where the results of that research, as well as of the research
done in-house, is transferred into technology. industry also benefits
greatly from the pool of condensed-matter physicists produced each
year by this country's universities and from those trained in postdoc-
toral programs at national laboratories. For their part, universities have
received support from industry in the form of grants of equipment,
funding for research projects, and support for graduate students. How-
ever, if the strongest possible coupling between universities, govern-
ment laboratories, and industry is to be achieved, the support of
university and laboratory research by industry should go well beyond
the mere provision offunds and equipment: research cooperation is also
required. At the same time, continuing efforts should be made to in-
crease the research cooperation between the national laboratories and
university scientists, since special facilities exist at the national
laboratories that are not available elsewhere. The realization of such
cooperation will require the coordinated efforts of universities and
industry, and of the federal government as well. The following recom-
mendations outline our views of the roles of each of these partners in
this process.
1. What government should do:
Establish policies, including tax incentives, to stimulate fundamental
research in industry.
Provide support for students engaged in cooperative university-
industry research.
Encourage and facilitate the flow of scientists between federal labora-
tories and universities for cooperative research programs.
Maximize access by outside users to the special facilities available
only at the federal laboratories.
2. What industry should do:
Increase the amount of in-house research even beyond the levels
directly supported by the policies suggested in point 1 above, i.e.,
through the use of corporate funds.
Establish and fund programs that enable industrial scientists to take
sabbatical leaves in universities and at national laboratories.
Receive university faculty and laboratory researchers in industrial
laboratories for sabbatical leaves and summers.
Provide direct support of faculty and departmental research grants
(e.g., the IBM programs).
Provide direct support of graduate and postdoctoral fellowships
(e.g., the IBM fellowship program).
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HIGHLIGHTS. OPPORTUNITIES. A ND NEEDS 35
Formulate cooperative research projects with graduate students
(e.g., the MIT-AT&T Bell Laboratories program).
Provide instrumentation for special facilities at national laboratories.
3. What universities should do:
Implement cooperative research and support programs with indus-
try, as MIT has done in materials processing.
Adopt a limited form of the "Japanese model" in which applied
physics research in high-technology areas, such as semiconducting
lasers, photonics, and electronics is supported by industrial firms
directly involved in the manufacture of materials, devices, compo-
nents, and systems employing these technologies.
Cooperate in the graduate training of industrial employees engaged
in applied research.
Arrange for sabbatical leave for federal laboratory researchers in
university departments. This support can take the form of direct
research contracts; the gift or loan of equipment, devices, and
components; and the support of graduate students.
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Representative terms from entire chapter:
occasional users
