• Mazzocchi, Tommaso Maria
• Gazzaneo, Paolo
• Werner, Daniel
• Arrigoni, Enrico

Abstract

<p>We investigate the photocurrent and spectral features in a simplified model of a Mott photovoltaic system consisting of a multilayered insulating heterostructure. The central correlated region is coupled to two metallic leads kept at different chemical potentials. A periodic drive applied to the correlated region produces excited doublons and holons across the Mott gap, which are then separated by a potential gradient, which mimics the polarization-induced electric field present in oxide heterostructures. The nonequilibrium Floquet steady-state is addressed by means of dynamical mean-field theory and its Floquet extension, while the so-called auxiliary master equation approach is employed as impurity solver. We find that impact ionization, identified by a kink in the photocurrent as function of the driving frequency, becomes significant and is generally favored by weak, narrowband hybridizations to the leads beyond a certain strength of the driving field. On the other hand, in the case of a direct coupling to metallic leads with a flat band, we observe a drastic reduction of impact ionization and of the photocurrent itself.</p>

Topics

• impedance spectroscopy
• theory
• strength