# Research Activity: Experimental Condensed Matter Physics

Division: Materials Sciences and Engineering

Primary Contact(s): James Horwitz (<james.horwitz@science.doe.gov>,
301-903-4894)

Team Leader: Harriet Kung (Acting)

Division Director: Harriet Kung

**Portfolio**

**Description:**

This program supports activities in experimental condensed matter
physics that emphasize the relationship between electronic structure and
the properties of complex systems whose behavior is often derived from
electron correlation. Major efforts are in systems that exhibit
correlated and emergent behavior with superconducting, semiconducting,
magnetic, thermoelectric, and optical properties. These efforts are
accompanied by activities to synthesize and characterize single crystals
to further explore and discover new and novel correlated electron
behavior. The program supports the development of new techniques and
instruments for characterizing the properties of these materials under
extreme conditions of ultra low temperature (mK) and ultra high magnetic
fields (100 T). One main emphasis of this activity is on the electron
dynamics of low dimensional systems. Confinement effects in high purity
semiconductors produce new forms of matter and new physical phenomena
such as the fractional Quantum Hall effect and Bose-Einstein
Condensates. These low dimensional systems and other nanophase materials
offer rich opportunities to explore their novel electronic behaviors. In
addition, this activity seeks to exploit ultrafast tools to manipulate
and probe the dynamic electronic behavior of condensed matter through
the development and applications of laser-driven, table-top x-ray
sources.

**Unique Aspects:**

The research on magnetism and magnetic materials has more emphasis and
direction than in other federally supported programs. It focuses on hard
magnet materials, such as those used for permanent magnets and in
motors, and on exchange biasing, such as used to stabilize the magnetic
read heads of disk drives and the influence of nm length scales on
magnetic materials properties. The Experimental Condensed Matter Physics
(ECMP) activity continues to support research on electronically complex
materials, an area that impacts a wide range of other topics including
superconductivity, magnetoresistivity, low-dimensional electron systems,
and magnetism including topics such as exchange bias and spin-polarized
electron transport. The combined projects in superconductivity comprise
a concerted and comprehensive energy-related basic research program. The
Department of Energy (DOE) national laboratories anchor the efforts and
maintain the integration with the Office of Electricity Delivery and
Energy Reliability (OE) developmental efforts. The 100 T multi-shot
magnet, under construction at the Los Alamos National Laboratory (LANL),
is a multidisciplinary project in many different areas of materials
design, materials research, and high power systems. Two major areas
research will be pursued upon completion of the magnet in 2006 which
include magnetic field induced phase transitions in addition to
nano-quantization and quantum size effect. The ECMP activity also has
unique thrusts in photoemission investigations of cuprate
superconductors. It is a source of new materials scientists through
strong programs at LANL, Sandia National Laboratories (SNL), Ames
Laboratory, Argonne National Laboratory (ANL), Brookhaven National
Laboratory (BNL), and the Stanford Linear Accelerator Center (SLAC)**.**
Internationally, the ECMP activity holds a position of world leadership
in the areas of magnetism, superconductivity, materials
characterization, and nanoscale science. New, exciting areas launched
within this activity in photonic band gap materials, 2-D electron
systems, magnetic superconductors and quasicrystals are now pursued
worldwide. Enhanced efforts are ongoing to generate high quality single
crystals of new materials at Ames, ANL, BNL, Oak Ridge National
Laboratory (ORNL), and SLAC.

**Relationship to Other** **Programs:**

This activity supports the National Academy of Science's Solid State
Sciences Committee, which in turn serves as a coordinating mechanism
nationally. It also supports topical activities at the National Academy
of Sciences which include the *Decadal Assessment and Outlook for the
Field of Condensed Matter and Materials Physics (CMMP) Research* and *An
Assessment of New Materials Synthesis and Crystal Growth in the United
States*. This research in the ECMP program is aimed at a fundamental
understanding of the electronic behavior of materials that underpin DOE
technologies. Improving the understanding of the physics of materials on
the nanoscale will be technologically significant as these structures
offer enhanced properties and could lead to dramatic improvements in
energy generation, delivery, utilization, and conversion technologies.
Specifically, research efforts in understanding the fundamental
mechanisms in superconductivity, the elementary energy conversion steps
in photovoltaics, and the energetics of hydrogen storage provide the
major scientific underpinnings for the energy technologies. The granular
materials research contributes to our understanding of radionuclide
transport in groundwater and is of direct relevance to the environmental
clean-up efforts. This activity also supports research of fundamental
interest for information technology and electronics industries in the
fields of semiconductor and spintronics research. These research efforts
are closely coordinated with other core research activities in BES,
including the Physical Behavior of Materials on photovoltaics, Synthesis
and Processing Science on single crystal growth, X-ray and Neutron
Scattering on photoemission studies, and Theoretical Condensed Matter
Physics on nanostructures and low-dimensional systems. They are also
coordinated with DOE technology programs in the Office of Energy
Efficiency and Renewable Energy (EERE), OE, and Office of Environmental
Management (EM).

**Significant Accomplishments:**

The ECMP activity has a long history of accomplishments dating back to
the 1950s and the first neutron scattering experiments at ORNL. Notable
accomplishments include the discovery of ion channeling and the
development of the field of ion implantation; the discovery of metallic
and strained-layer superlattices; the establishment of the field of
thermoacoustics and thermoacoustic refrigeration and heating; the
invention of Z-contrast scanning transmission electron microscopy; the
theoretical and predictive basis for photonic band gap materials; the
tandem photovoltaic cell; the observation of stripes in superconductors,
the invention of a Josephson junction scanning tunneling microscope and
the first observation of superconductivity in a magnetically doped
semiconductor (PtSb~2~ with \~1% Yb), the observation of Bose
condensation of excitons doped double layer semiconductor structures,
and the characterization of BCS and 2 Gap Superconductivity in magnesium
diboride (MgB~2~). In addition, the activity has supported much of the
seminal work in the fields of high temperature superconductors and
quasicrystals, efforts now pursued worldwide.

**Mission Relevance:**

This activity provides direct research assistance to the technology
program in OE on superconductivity. In addition, it supports, more
fundamentally, several DOE technologies and the strategically important
information technology and electronics industries through its results in
the fields of semiconductor physics and electronics research; the
petroleum recovery efforts of the Office of Fossil Energy (FE); and the
clean-up efforts of EM through research on granular materials and on
fluids; and the R&D on advanced materials and magnets and
thermoelectrics of EERE.

**Scientific Challenges:**

Among the immediate on-going scientific challenges are: the solution of
the mechanism for high temperature superconductivity; the understanding
of "stripes" in correlated electron systems; the understanding of novel
quantum effects and of "emergent phenomena," that is, new phenomena that
emerge when the complexity of a system grows with the addition of more
particles; the development of a very high-magnetic field research
program to exploit the 100T and 60T magnets at LANL; research in
nanoscale science; low-temperature physics; and the continued
development of a materials synthesis and crystal growth capability in
this country. Quality materials lie at the heart of quality
measurements: a thrust to develop a core competence in the synthesis of
new materials and the growth of crystals is underway, and it will
continue to be a priority. High-magnetic-field research coupled with low
temperature physics led to the discovery of the quantum Hall effect and
to the general area of novel quantum effects. The availability of very
high magnetic fields over useable time scales, as will be afforded by
the new magnets at LANL, offers the promise of both increasing the
fundamental understanding of matter and of observing the effects of very
high magnetic fields on materials properties. This will undoubtedly lead
to the discovery of new and exciting physics. Similarly, low temperature
physics continues to be important for the advancement of physics by
providing the experimental conditions necessary to observe phenomena
such as BEC, the quantum Hall effect, and superconductivity. Developing
and understanding matter and materials at the nano- and subnanoscale is
a critical need because electronic, optical, and magnetic devices
continue to shrink in size. Ballistic transport in quantum wires
exceeding 5 µm in length may provide the basis for quantum computing.

**Funding Summary:**

Dollars in Thousands

  ----------------- ----------------- ----------------- -----------------
                                                        

                                                        
  ----------------- ----------------- ----------------- -----------------

[FY 2005]{.underline} [FY 2006]{.underline} [FY 2007]{.underline}
[Request]{.underline}

> 41,024 36,691 47,480
>
> [Performer]{.underline} [Funding Percentage]{.underline}
>
> DOE Laboratories 77%
>
> Universities 23%

These are percentages of the operating research expenditures in this
area; they do not contain laboratory capital equipment, infrastructure,
or other non-operating components.

**Projected Evolution:**

The Experimental Condensed Matter Physics activity will include further
work at the nanoscale; the development of a very high magnetic field
research program; and continued development of the materials synthesis
and crystal growth thrust. The portfolio can be expected to continue
thrusts in electronic structure, new materials, surfaces/ interfaces,
and experimental techniques. For example, sum frequency generation is a
new technique that is now being used to probe the electronic and
vibrational structure of chiral molecules on surfaces. Femtosecond
time-resolved magnetooptical, tehahertz and x-ray diffraction techniques
will be used to study the coupled dynamics of charge carriers along with
the associated lattice deformations in high temperature superconductors,
colossal magneto-resistance manganites and charge density wave
conductors. The subtopics also will be the similar, e.g., magnetism, low
dimensional electron systems, and new materials. Low temperature physics
and superconductivity are important. Low temperature physics underlies
several other areas of opportunity and presents issues of its own.
Superconductivity, specifically high temperature superconductivity,
continues to be a potentially revolutionizing technology. The goal for
the former is to augment the investment in low temperature physics when
possible. In superconductivity, the goal is to identify the most
pressing scientific issues and ensure the level of effort is consistent
with the priorities. New investigations in the Casimir force have been
initiated. This attractive force between two surfaces in a vacuum
predicted over 50 years ago could affect everything from micromachines
to unified theories of nature.