CWRU Physics Faculty
Associate Professor of Physics
B. Tech., Indian Institute of Technology, Kanpur (1987)
Ph.D., Yale University (1994)
Theoretical Physics: Condensed matter physics, Particle-Astrophysics and
The main focus of my research is condensed matter theory. A second area of interest is theoretical particle astrophysics and cosmology. In condensed matter physics my main interests are quantum many body physics and quantum effects in disordered materials. In particle astrophysics and cosmology I am interested in how high energy phenomena shaped the early Universe, the cosmic microwave background as a probe of the early universe and in non-perturbative phenomena in quantum field theory.
Representative past work in condensed matter theory includes the prediction that quantum interference would make the conductance of semiconductor rings oscillate in response to electric fields due to their coupling to the electron spin ("Aharonov-Casher effect") . This prediction was recently verified experimentally. Similarly my collaborators and I predicted that quantum interference effects can be used to probe the roughness of the semiconductor-oxide interface in silicon MOSFETs, the fundamental building blocks of semiconductor electronics . I have applied methods of supersymmetric quantum field theory to understand the propagation of electrons in semiconductors under conditions of broken time reversal symmetry (for example under the conditions of the quantum Hall effect) . A remarkable experimental development of the past two decades is the ability to engineer quantum dots - small electronic devices that are essentially large artificial atoms. I have studied the stability of electronic matter in these devices. Their physics is controlled by the interplay of chaotic electronic motion and electron-electron interaction .
My recent work on cosmology is focussed on the observable consequences of a phase transition in the early Universe on the grand unification energy scale. We have predicted that such a transition will produce gravitational radiation that may produce an observable imprint on the cosmic microwave background .
Other interests that are more difficult to classify (art history, the history of physics) are represented by publications  and  in the list of representative publications.