My general area of research is theoretical condensed matter physics and quantum materials. I am currently working in the two areas of superconductivity and graphene-based materials.
Superconductivity is a phenomenon occurring at very low temperatures approaching absolute zero (-273C) where certain materials lose all resistance to the flow of electrical current and become perfect conductors. In recent times new families of superconductors have been discovered at a phenomenal rate. A major breakthrough came in 1986 with the discovery of the cuprate materials which superconduct at much higher temperatures than previously known. This mobilized unprecedented activity amongst scientists around the world due to the potential for applications and improvement in existing applications. Superconductors are used in a range of applications such as the high speed MAGLEV (Magnetic Levitation) train being implemented in Japan, superconducting cables for power transmission, industrial magnets, medical diagnosis with MRI (Magnetic Resonance Imaging), etc. In addition, they are being developed as microwave filters for the communication industry and investigated for possible use in quantum computing. My own work has centered around calculating various experimental properties in order to test theories for the various manifestations of superconductivity occurring in newer materials. One of our group highlights was to propose a new experimental probe [angle-resolved specific heat (ARSH)] for determining the symmetry of the order parameter in exotic superconductors. This is done via measurements of the specific heat in rotated magnetic field. This proposal has been implemented by several groups in the U.S.A., the U.K. and Japan and has been shown to be successful in many materials. Identifying the symmetry of of the order parameter is felt to be key to identifying the mechanism of the superconductivity which in turn may lead to the discovery of new superconductors.
Graphene, a single sheet of carbon atoms, is a material which shows highly unusual properties because the electrons act like they have no mass. Isolated for the first time in 2004, this material may be able provide tests of fundamental quantum physics (notably the Dirac Hamiltonian for massless fermions) in addition to potentially revolutionizing microelectronics. Graphene has the highest charge mobility seen in materials at room temperature and can be patterned directly into an electronic device, including the contacts. Indeed, a single electron transistor has already been made from graphene. In addition to potential for fast electronics, graphene has unusual properties which may facilitate its use in surface coatings and photovoltaics. For instance, graphene might some day replace the current materials used in LCD displays. My research in this area has been on the topic of calculating the optical properties of monolayer and bilayer graphene which is important both for technological applications and also for understanding the unusual quantum physics seen in this material.