Multidimensional spectroscopy of topological insulators

Spectroscopic tools provide valuable information about the microscopic degrees of freedom and dynamics of many-body systems. Among them, multidimensional spectroscopy has been attracting increasing attention in the past few years. The multidimensional spectrum of a system corresponds to its response to a train of time-spaced electromagnetic pulses and contains information that is not easily accessible in standard single-pulse spectroscopy. For instance, it has been demonstrated that the multidimensional spectrum can resolve excitations that are entangled in linear response, resolve homogeneous and inhomogeneous broadening, and provide information about quasiparticle lifetime and interactions. In this talk, we present the theoretical results of the multidimensional spectrum of topological insulators (TIs). Using minimal models for TIs, we contrast the multidimensional spectral features in the topological and trivial regimes. We also show that multidimensional spectroscopy can resolve the tilting angle of the massive bulk Dirac cones for non-centrosymmetric TIs.