**Rutgers University Department of Physics and
Astronomy **

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The Rutgers faculty in condensed matter theory have interests spanning many
areas including: new phases of quantum matter, highly-correlated electron
phenomena, such as high-temperature superconductivity, magnetism, quantum phase
transitions, oxide and heavy-fermion physics; physics at surfaces, including
dynamic phenomena and electronic and geometrical structure; quantum liquids
including superfluids and Bose Einstein condensates; equilibrium and
non-equilibrium statistical mechanics including the physics of glasses and
quantum dots; quantum computation, first principles calculations of electronic
and structural properties, including the applications of dynamical mean field
theory; quantum phase transitions and critical phenomena; semiconductor
physics; quantum statistical mechanics and field theory; thermodynamics,
transport and localization in disordered systems. At

**Professor Natan Andrei**

I am interested in strongly correlated electron systems, particularly low dimensions where quantum fluctuations are enhanced and lead to new and often unexpected phenomena. Also, low dimensional many-body systems can be studied by powerful mathematical tools that yield non-perturbative results such as conformal field theory, bosonization and the Bethe-Ansatz. Most recently I have studied transport properties of quantum dots in and out of equilibrium, thermal conductivity in spin chains and ladders and the exact solutions of a variety of quantum impurity models.

**Professor Premala Chandra**

I am interested in a wide variety of subjects in condensed matter physics.
One area of my work concerns new forms of quantum equilibrium order - anything
from frustrated quantum spin systems to novel forms of quantum order in
strongly correlated electron systems. In my group we are trying to understand
the emergence of new types of behavior in non-equilibrium matter. One topic of
particular interest is glasses - where matter undergoes a transition to a state
which moves infinitely slowly, and which remembers its past. Together with Lev
Ioffe and Michael Gershenson, we are trying to design and fabricate a new class
of quantum qubit as the elementary element of tomorrows "quantum
computers". This requires a fine balance of good theory and contact with
real-world experiment. Another area of my work is in magneto-electrics, where
my group is working in collaboration with Experimentalist Sang Cheong and
collaborator Karin Rabe, to understand and develop new classes of hybrid
magneto-electric materials. I have recently moved to

**Professor Piers Coleman**

It is a very exciting time for condensed matter physics. This decade may well be like the late 1960s, a time when a convergence of particle physics and condensed matter physics led to the great revolution of understanding in classical criticality. Today, the same sort of sea-changes in our understanding of quantum matter are taking place, with the discovery of "quantum criticality" and quantum phase transitions. My research is concerned with the fundamentally new classes of collective condensed matter behavior that emerge in complex materials. Recently, I have been particularly interested in quantum phase transitions - which give rise to the formation of new classes of strange metals and nucleate new forms of quantum order, such as high temperature superconductors. I have active research activities in the subject of heavy fermion physics and also on strongly correlated mesoscopic systems such as quantum dots. I try to maintain a research portfolio that balances phenomenology and close contact with experiment, with the development of state-of-the-art mathematical tools for many body systems (such as the Slave boson). I'm constantly on the look out for talented young people who'd like to collaborate with this research.

**Professor Kristjan Haule**

We want to gain theoretical understanding of the behavior of real materials which fall under the rubric of strongly correlated electron systems. These are complex materials, with electrons occupying active 3d-, 4f- or 5f-orbitals. Recent advance in combining the well established electronic structure methods with the modern many body tools, such as Dynamical Mean Field theory and its cluster extensions, allows us for the first time, to carry out the first principle calculations for some complex correlated materials, such as the heavy fermions, doped Mott insulators, fullerens and many others. Together with the group of Gabriel Kotliar, we are trying to develop advanced methods and techniques that would allow us to explain and ultimately predict the properties of any correlated solid with a click of a mouse. The computer aided material design is now a promising research direction and the ability to predict physical properties of strongly correlated materials with many unusual properties makes the prospects for applications particularly exciting.

**Professor George K. Horton**

I have recently become interested in the subject of intrinsic localized
modes of vibration in perfect crystals, often called breathers. The possibility
that such excitations might exist was first broached by Sievers and Takeno in
Phys. Rev. Lett. 61, 970 (1988). They represent a strictly anharmonic effect.
Theoretically there seems to be no reason to believe that they do not exist and
they have been observed in special systems, i.e. micromechanical cantilever
arrays. The theoretical work has been reviewed by Sievers and Page in
"Dynamical Theory of Solids", edited by Horton and Maradudin,
Elsivier,

**Professor Lev Ioffe**

I am interested in many areas of theoretical condensed matter physics. Generally, I am interested in all aspects of strongly correlated and disordered electron systems but I am especially interested in the interplay between the disorder and a strong interaction. Currently, I am working on diverse problems related to quantum computation by solid state devices and on the physics of strongly interacting disordered electron systems. Specifically, I work on the formation of topologically protected states in Josephson junction arrays that can be used for quantum computation and on the microscopic sources of dephasing in the setups proposed for quantum computations that have been implemented in the laboratory. In the subfield of disordered systems I work on the glass formation in the materials with low density of the electrons where glassiness is due to the frustration induced by combination of the disorder and the long range Coulomb repulsion. Recently I started to work on a different set of problems related to the competition of superconductivity and localization, the physics of these problems (dominated by attraction instead of repulsion) is completely different but no less exciting. In my research I try to put the emphasis on the qualitative picture of the physical phenomena and so I prefer to use analytical tools of the modern condensed matter theory over the numerics that I resort to only when really unavoidable. The list of my recent publications and some recent papers on these subjects can be found at http://echidna.rutgers.edu/

**Professor Gabriel Kotliar**

We apply methods of quantum statistical mechanics quantum field theory and computational physics to treat fundamental problems in material science and condensed matter physics. My main interest in the area of disordered and strongly interacting electronic systems. Problems of current interest include the metal-insulator transition in doped semiconductors, the physical properties of transition metal oxides and the phenomena of high temperature superconductivity, the non linear optical properties of artificially fabricated semiconductor systems and the anomalous non equilibrium phenomena in glasses.

**Professor David Langreth**

Density functional theory of the type that led to the recent Nobel prize for Walter Kohn of UCSB provides the method of choice for the calculation of electronic structure of wide classes of dense condensed matter as well as isolated molecules. However, it has been singularly unsuccessful for sparse, soft, and much biological matter, which is equally abundant and important, because if fails to account for the long-range van der Waals or dispersion interactions. We have recently developed a generalization of density functional theory that shows great promise to extend its success to this wider class of important problems. We have sucessfuly tested the theory on a wide variety of van der Waals systems including sparse layered solids, a polymer crystal, and molecular van der Waals complexes. We have recently had success in the application to the base pair stacking problem in DNA, and and our theory predicts an average DNA twist per step of 34 degrees, which is very close to the experimental number of 36 degrees, while predicted sequence dependent twists also match trends in high resolution experimental data. We are currently applying our theory to sequence dependent protein binding to DNA, as well as to the molecules that intercalate between DNA base pairs; the latter are important for drug action and design, including antibacterials and cancer treatments. In another project we apply our theory to the so called metal-organic-framework (MOF) materials. These are open structure solid crystals, which are a candidate to solve the hydrogen storage problem in vehicles in a future hydrogen economy. This project is a collaboration with two experimental colleagues.

**Professor Paul Leath**

My recent research interests have been in the area of breakdown phenomena in disordered materials, e.g. brittle fracture, electrical breakdown, and the critical current in superconductors. Most recently, we have studied the crossover from tough to brittle fracture in heterogeneous and composite materials by both analytic and numerical simulation techniques. I have also explored the role of vortex line creation at defects and their subsequent motion on the behavior near the critical current in superconducting arrays of Josephson junctions. For many years, I have also been interested in phenomena near percolation threshold, where rigidity fails and the elastic constants go to zero even though the material is still connected. Also, I have plans to work again on phonons and spin wave excitations in disordered materials.

**Professor Karin M. Rabe**

The research in my group currently centers on the theoretical investigation of complex oxides. Chemical and structural complexity has proved to be an critical factor in producing a variety of fascinating properties of solids, including ferroelectricity, large piezoelectric and dielectric responses, and multiferroicity in metals and insulators, as well as quasicrystallinity and high-temperature superconductivity. Current research projects in my group include work on ferroelectric epitaxial thin films and superlattices and other artificially structured oxide materials, novel mechanisms for ferroelectricity in magnetic oxides, and development of multiscale methods for studying complex-oxide structural phase transitions at nonzero temperature. First-principles density-functional methods are used both directly and in the construction of first-principles effective Hamiltonians for theoretical prediction and analysis of properties of materials, both real and as-yet hypothetical, in bulk and thin film forms.

**Professor ****David
Vanderbilt**

In recent decades, first-principles methods of computational electronic-structure
theory have provided extremely powerful tools for predicting the electronic and
structural properties of materials, using only the atomic numbers of the atoms
and some initial guesses at their coordinates as input. My principal interests
are in applying such methods to study the dielectric, ferroelectric,
piezoelectric, and magnetoelectric properties of oxides. These may be simple
bulk materials, or they may be superlattices or other nanostructured composites
in which surface and interface effects are important. I also have an abiding
interest in the development of new theoretical approaches and computational
algorithms that can extend the reach and power of these first-principles
methods. In particular, our group has made contributions to pseudopotential
theory, the theory of electric polarization, the study of insulators in finite electric
fields, the theory of Wannier functions and their applications, and the role of

**Professor Emil Yuzbashyan**

My research focuses on the theory of strongly interacting and disordered systems. I am interested in new types of correlated states that arise in ultra-cold atomic gases, disordered superconductors, nanometer scale superconductors, semiconductor quantum dots, quantum wires, etc. Interplay between interactions, disorder, and small size in these systems presents a significant challenge and often renders conventional approaches inadequate. I am also interested in the theory of superfluidity and superconductivity in new regimes, unconventional superconductivity, far from equilibrium many-body systems, interacting spin systems, physical properties of integrable or nearly integrable systems, and dephasing and dechoherence in quantum devices due to their coupling to the environment.

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Revised June, 2010