Superconductivity in Semiconductor Structures: the Excitonic Mechanism

TL;DR

This paper theoretically investigates how exciton-polariton mediated interactions can induce superconductivity in semiconductor structures, showing that critical temperature depends on boson and electron densities, with potential for high-temperature superconductivity in GaAs microcavities.

Contribution

It introduces a model for exciton-mediated superconductivity in 2D semiconductor structures and predicts high critical temperatures near 50K, highlighting the effects of density variations.

Findings

Critical temperature increases with boson density.

Critical temperature decreases with 2DEG density.

Superconductivity can reach near 50K in GaAs microcavities.

Abstract

We study theoretically the effect of the fermion and boson densities on the superconductivity transition critical temperature $(T_c)$ of a two dimensional electron gas (2DEG), where superconductivity is mediated by a Bose-Einstein condensate of exciton-polaritons. The critical temperature is found to increase with the boson density, but surprisingly it decreases with the 2DEG density increase. This makes doped semiconductor structures with shallow Fermi energies better adapted for observation of the exciton-induced superconductivity than metallic layers. For the realistic GaAs-based microcavities containing-doped and neutral quantum wells we estimate $T_c$ as close to 50K. Superconductivity is suppressed by magnetic fields of the order of 4T due to the Fermi surface renormalisation.