DC electric field driven discretization of single-particle excitation spectra in a Mott insulator

Abstract

We theoretically investigate the single-particle excitation spectra of a one-dimensional Hubbard model at half filling using an infinite matrix-product state and elucidate the discretized energy spectra emerging under the influence of a dc electric field. In a weak electric-field regime, we observe two kinds of spectral structures in the density of states. With increasing the electric-field strength, the discretized spectra, the period of which is proportional to the strength, become dominant, and the density of states exhibits the Wannier-Stark ladder in their spectra. In addition, we also simulate time- and angle-resolved photoemission spectroscopy using an ultrashort terahertz pump pulse that approximates a dc electric field. Our results represent a significant step forward in understanding the states in strongly correlated electron systems driven by a static electric field.