Theory projects in the Srivastava lab seek to relate non-trivial Bloch band geometry to observable responses of solid state systems, particularly transition metal dichalcogenides and Dirac materials such as Weyl semimetals. A non-trivial geometry of electronic bands in a solid can result in effective electromagnetic fields in the reciprocal space. Can we use light to tune such fields? Is it possible to induce non-trivial geometry and topological states of light/matter using light-matter interactions? Our research hopes to address these questions.

Current projects explore the role Berry curvature and the quantum Fubini-Study metric beyond the single-particle paradigm, in interacting systems such as excitons and other low energy excitations.¹ We are also investigating the role of the quantum metric and Berry curvature in the dynamics of localized Bloch electrons via the semiclassical wave packet formulation of electron dynamics.

¹“Signatures of Bloch-band geometry on excitons: Nonhydrogenic spectra in transition-metal dichalcogenides,” A. Srivastava and A. Imamoglu, Phys. Rev. Lett. 115, 166802 (2015).