Department of Physics

condensed matter physics (experimental)

Research in my lab concentrates on experimental studies of the dynamics of electrons in disordered materials and on waves in artificial structures.

The study of disordered materials is challenging in a number of interesting ways. Most obviously, electrons will not form Bloch waves as they do in crystalline materials, but in addition, the disorder enhances the effects of electron-electron interactions and, in the case of strong disorder, leads to localization of the electronic states. There are further questions about the role of the intrinsic local inhomogeneity in the nature of the electronic states.

Dynamical experiments are useful as a way of probing the motion of electrons in their disordered environment; if the frequencies are sufficiently high, one directly observes the quantum-mechanically coherent response of the electrons. Near quantum-critical transitions, the response is dominated by quantum fluctuations. For example, near the disorder-driven metal-insulator transition the conductivity and dielectric responses become intrinsically scale-dependent in time and space as the system fluctuates between conducting and non-conducting ground states.

Disordered materials often have unique magnetic properties as well. In many systems, the relationship between the electric and magnetic properties remains largely unexplored.