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A Pair of 2D Quantum Liquids: Investigating the Phase Behavior of Indirect Excitons.

ABSTRACT: Long-lived indirect excitons (IXs) exhibit a rich phase diagram, including a Bose-Einstein condensate (BEC), a Wigner crystal, and other exotic phases. Recent experiments have hinted at a "classical" liquid of IXs above the BEC transition. To uncover the nature of this phase, we use a broad range of theoretical tools and find no evidence of a driving force toward classical condensation. Instead, we attribute the condensed phase to a quantum electron-hole liquid (EHL), first proposed by Keldysh for direct excitons. Taking into account the association of free carriers into bound excitons, we study the phase equilibrium between a gas of excitons, a gas of free carriers, and an EHL for a wide range of electron-hole separations, temperatures, densities, and mass ratios. Our results agree reasonably well with recent measurements of GaAs/AlGaAs coupled quantum wells.

SUBMITTER: Wrona PR

PROVIDER: S-EPMC9527805 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature

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A Pair of 2D Quantum Liquids: Investigating the Phase Behavior of Indirect Excitons.

Wrona Paul R PR Rabani Eran E Geissler Phillip L PL

ACS nano 20220907 9

Long-lived indirect excitons (IXs) exhibit a rich phase diagram, including a Bose-Einstein condensate (BEC), a Wigner crystal, and other exotic phases. Recent experiments have hinted at a "classical" liquid of IXs above the BEC transition. To uncover the nature of this phase, we use a broad range of theoretical tools and find no evidence of a driving force toward classical condensation. Instead, we attribute the condensed phase to a quantum electron-hole liquid (EHL), first proposed by Keldysh f ...[more]

PMID: 36069715

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