Effects of density imbalance on the BCS-BEC crossover in semiconductor electron-hole bilayers

Abstract

We study the occurrence of excitonic superfluidity in electron-hole bilayers at zero temperature. We not only identify the crossover in the phase diagram from the BCS limit of overlapping pairs to the BEC limit of non-overlapping tightly-bound pairs but also, by varying the electron and hole densities independently, we can analyze a number of phases that occur mainly in the crossover region. With different electron and hole effective masses, the phase diagram is asymmetric with respect to excess electron or hole densities. We propose as the criterion for the onset of superfluidity, the jump of the electron and hole chemical potentials when their densities cross.

4 pages, 3 figures

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• Phase diagram of a cold polarized Fermi gas
• Two-species fermion mixtures with population imbalance
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• Trapping of Cold Excitons with Laser Light
• Coherence Length of Cold Exciton Gases in Coupled Quantum Wells
• Evaluating the phase diagram of superconductors with asymmetric spin populations
• Ultracold polarized Fermi gas at intermediate temperatures

Cited by in corpus (18)

• BEC-BCS Crossover in the Nambu--Jona-Lasinio Model of QCD
• Superfluidity at the BEC-BCS crossover in two-dimensional Fermi gases with population and mass imbalance
• Enhancement of electron-hole superfluidity in double few-layer graphene
• Atypical BCS-BEC crossover induced by quantum-size effects
• Enhanced critical temperature, pairing fluctuation effects, and BCS-BEC crossover in a two-band Fermi gas
• Multicomponent electron-hole superfluidity and the BCS-BEC crossover in double bilayer graphene
• Supersolidity in electron-hole bilayers with a large density imbalance
• Possible effect of collective modes in zero magnetic field transport in an electron-hole bilayer
• Roton-maxon spectrum and instability for weakly interacting dipolar excitons in a semiconductor layer
• Polaron spectroscopy of interacting Fermi systems: insights from exact diagonalization
• Biexciton-like quartet condensates in an electron-hole liquid
• Anisotropic superfluidity of two-dimensional excitons in a periodic potential
• Anomalous Josephson effect of s-wave pairing states in chiral double layers
• Structure of exciton condensates in imbalanced electron-hole bilayers
• Josephson effect as signature of electron-hole superfluidity in bilayers of van der Waals heterostructures
• 2D bilayer electron-hole superfluidity with unequal and anisotropic masses
• Unconventional superconductivity mediated by exciton density wave fluctuations
• Beyond Random Phase Approximation in electron-hole bilayer superfluidity