Potential Inhomogeneities in Presence of Strong Interactions: Birth and Death of Superconductors
Tata Institute of Fundamental Research, India
Strong repulsive interactions and potential inhomogeneities both tend to localize Fermions on a lattice and lead to loss of superconductivity. The natural question that comes up is whether they compete or complement each other when both are present in a system at the same time. In this talk, we will use a effective Hamiltonian approach which treats both interactions and inhomogeneities on the same footing to look at two systems: (a) the Ionic Hubbard Model at half-filling, where a staggered potential on a bipartite lattice competes with interactions to delocalize charge and give birth to a novel superconductor. The superconducting Tc scales with the bandwidth of the system and shows a non-monotonic behaviour with the staggered potential, (b) the disordered Hubbard model away from half-filling, where weak disorder competes with strong interaction to preserve superconductivity, but strong disorder complements interactions leading to sudden death of superconductivity in this system.
Hosted by Dong-Ling Deng.
NOTE: Dr. Sansarma will be present at the University of Maryland from October 5th to October 10th. If you're interested in meeting him personally, use the sign-up sheet here.
2205 John S. Toll Physics Building