Keldysh field theory of dynamical exciton condensation transitions in nonequilibrium electron-hole bilayers

• Published in: arXiv.org
• Main Authors: Zeng, Yongxin, Crépel, Valentin, Millis, Andrew J
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 03.07.2024
• Subjects: Bias; Energy gap; Excitons; Field theory; Holes (electron deficiencies); Interlayers; P waves; Physics - Mesoscale and Nanoscale Physics; Physics - Strongly Correlated Electrons; Quantum wells; Transition metal compounds
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2311.04074

Recent experiments have realized steady-state electrical injection of interlayer excitons in electron-hole bilayers subject to a large bias voltage. In the ideal case in which interlayer tunneling is negligibly weak, the system is in quasi-equilibrium with a reduced effective band gap. Interlayer tunneling introduces a current and drives the system out of equilibrium. In this work we derive a nonequilibrium field theory description of interlayer excitons in biased electron-hole bilayers. In the large bias limit, we find that p-wave interlayer tunneling reduces the effective band gap and increases the effective temperature for intervalley excitons. We discuss possible experimental implications for InAs/GaSb quantum wells and transition metal dichalcogenide bilayers.