## LOW-DIMENSIONAL SYSTEMS

*Professors Igor Aleiner, Cory Dean, Tony Heinz, Andrew Millis, Abhay Pasupathy, Aron Pinczuk & Tomo Uemura*

We concern ourselves with the electronic properties of lower-dimensional electron systems as they occur in semiconductors and also in extended molecules. Two-dimensional electron systems at the interface of ultra-pure semiconductors show fascinating properties such as the fractional quantum Hall effect and quantum phase transitions. We are getting increasingly involved in the mesoscopic electronic and thermal transport in various nanoscale systems including organic molecules, carbon nanotubes and other one-dimensional quantum wires using state-of-art modern nanofabrication processes and scanned probe techniques.

## OPTICAL SPECTROSCOPY, NONLINEAR OPTICS & PHOTON ECHOES

*Professors Tony Heinz, Andrew Millis & Aron Pinczuk*

Interactions of light and matter have created new tools that allow us to probe the dynamics of material systems and to characterize the confinement of electron states, and the collective behaviors of charge carriers in quantum wells, quantum wires and quantum dots. Using ultrafast optoelectronics, optical spectrosocpy and inelastic light scattering, we investigate various topics such as elementary excitations of electron quantum liquids in two-dimensional systems; surface dynamics and surface process control; and photon echoes and superfluorescenc. Optical conductivity of correlated electron systems and theory of Raman scattering in nanostructures are among the activities of the theory group. __link__

SUPERCONDUCTIVITY AND STRONGLY CORRELATED SYSTEMS

*Professors Igor Aleiner, Boris Altshuler, Cory Dean, Andrew Millis, Abhay Pasupathy & Tomo Uemura *

Strongly correlated electrons in condensed matter produce numerous exciting and exotic states of matter such as superconductivity and mangnetism. We have performed extensive experimental studies in high-Tc cuprate, organic, heavy-fermions, and other superconductors and their family materials using muon spin relaxation and neutron scattering techniques. We use atomic-resolution scanning tunneling microscopy to understand the low energy quantum states of these strongly correlated materials. In addition to these experimental efforts, understanding novel states of matter exhibited by these strongly interacting electrons, such as novel behavior near a quantum critical point in a 'strongly correlated' metal, is one of the central goals of the condensed matter theory group.

## STATISTICAL PHYSICS AND NONLINEAR PHENOMENA

*Professors Timothy Halpin-Healy* and David Reichman (Chemistry)

Soft condensed matter physics is the study of materials, such as fluids, liquid crystals, polymers, colloids, and emulsions, as well as glasses and supercooled liquids. These systems exhibit complex statistical behavior, very slow convergence to equilibium and nonlinear phenomena.