The superfluid phase transition in two-dimensional excitonic systems

Abstract

We study the superfluid phase transition in the two-dimensional (2D) excitonic system. Employing the extended Falicov-Kimball model (EFKM) and considering the local quantum correlations in the system composed of conduction band electrons and valence band holes we demonstrate the existence of the excitonic insulator (EI) state in the system. We show that at very low temperatures, the particle phase stiffness in the pure-2D excitonic system, governed by the non-local cross correlations, is responsible for the vortex-antivortex binding phase-field state, known as the Berezinskii-Kosterlitz-Thouless (BKT) superfluid state. We demonstrate that the existence of excitonic insulator phase is a necessary prerequisite, leading to quasi-long-range order in the 2D excitonic system.

7 pages, 3 figures (in the arXive version), 6 pages, 3 figures (in the published version)

References in corpus (4)

• Coulomb Drag in the Exciton Regime in Electron-Hole Bilayers
• Critical Point of an Interacting Two-Dimensional Atomic Bose Gas
• Anomalous Coulomb drag in electron-hole bilayers
• Strongly Interacting Two-Dimensional Bose Gases

Cited by in corpus (4)

• Probing phase coherence via density of states for strongly correlated excitons
• Phase coherence and spectral functions in the two-dimensional excitonic systems
• Density of states and excitonic condensation in the double layer correlated systems
• Density of states in the bilayer graphene with the excitonic pairing interaction