Dynamical instability of a driven-dissipative electron-hole condensate in the BCS-BEC crossover region

Ryo Hanai, Peter B. Littlewood, Yoji Ohashi

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

We present a stability analysis on a driven-dissipative electron-hole condensate in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover region. Extending the combined BCS-Leggett theory with the generalized random phase approximation to the nonequilibrium case by employing the Keldysh formalism, we show that the pumping and decay of carriers causes a depairing effect on excitons. This phenomenon gives rise to an attractive interaction between excitons in the BEC regime, as well as a supercurrent that anomalously flows antiparallel to θ(r) [where θ(r) is the phase of the condensate] in the BCS regime, both leading to dynamical instabilities of an exciton BEC. Our results suggest that a substantial region of the exciton-BEC phase in the phase diagram (in terms of the interaction strength and the decay rate) is unstable.

Original languageEnglish
Article number125206
JournalPhysical Review B
Volume96
Issue number12
DOIs
Publication statusPublished - 2017 Sep 28
Externally publishedYes

Fingerprint

Excitons
condensates
crossovers
excitons
Electrons
Bose-Einstein condensation
BCS theory
decay rates
Phase diagrams
pumping
condensation
phase diagrams
interactions
formalism
LDS 751
causes
decay
approximation

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Dynamical instability of a driven-dissipative electron-hole condensate in the BCS-BEC crossover region. / Hanai, Ryo; Littlewood, Peter B.; Ohashi, Yoji.

In: Physical Review B, Vol. 96, No. 12, 125206, 28.09.2017.

Research output: Contribution to journalArticle

@article{e4c1cbb1c6f845c8ac1477edf64fa29c,
title = "Dynamical instability of a driven-dissipative electron-hole condensate in the BCS-BEC crossover region",
abstract = "We present a stability analysis on a driven-dissipative electron-hole condensate in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover region. Extending the combined BCS-Leggett theory with the generalized random phase approximation to the nonequilibrium case by employing the Keldysh formalism, we show that the pumping and decay of carriers causes a depairing effect on excitons. This phenomenon gives rise to an attractive interaction between excitons in the BEC regime, as well as a supercurrent that anomalously flows antiparallel to θ(r) [where θ(r) is the phase of the condensate] in the BCS regime, both leading to dynamical instabilities of an exciton BEC. Our results suggest that a substantial region of the exciton-BEC phase in the phase diagram (in terms of the interaction strength and the decay rate) is unstable.",
author = "Ryo Hanai and Littlewood, {Peter B.} and Yoji Ohashi",
year = "2017",
month = "9",
day = "28",
doi = "10.1103/PhysRevB.96.125206",
language = "English",
volume = "96",
journal = "Physical Review B-Condensed Matter",
issn = "2469-9950",
publisher = "American Physical Society",
number = "12",

}

TY - JOUR

T1 - Dynamical instability of a driven-dissipative electron-hole condensate in the BCS-BEC crossover region

AU - Hanai, Ryo

AU - Littlewood, Peter B.

AU - Ohashi, Yoji

PY - 2017/9/28

Y1 - 2017/9/28

N2 - We present a stability analysis on a driven-dissipative electron-hole condensate in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover region. Extending the combined BCS-Leggett theory with the generalized random phase approximation to the nonequilibrium case by employing the Keldysh formalism, we show that the pumping and decay of carriers causes a depairing effect on excitons. This phenomenon gives rise to an attractive interaction between excitons in the BEC regime, as well as a supercurrent that anomalously flows antiparallel to θ(r) [where θ(r) is the phase of the condensate] in the BCS regime, both leading to dynamical instabilities of an exciton BEC. Our results suggest that a substantial region of the exciton-BEC phase in the phase diagram (in terms of the interaction strength and the decay rate) is unstable.

AB - We present a stability analysis on a driven-dissipative electron-hole condensate in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover region. Extending the combined BCS-Leggett theory with the generalized random phase approximation to the nonequilibrium case by employing the Keldysh formalism, we show that the pumping and decay of carriers causes a depairing effect on excitons. This phenomenon gives rise to an attractive interaction between excitons in the BEC regime, as well as a supercurrent that anomalously flows antiparallel to θ(r) [where θ(r) is the phase of the condensate] in the BCS regime, both leading to dynamical instabilities of an exciton BEC. Our results suggest that a substantial region of the exciton-BEC phase in the phase diagram (in terms of the interaction strength and the decay rate) is unstable.

UR - http://www.scopus.com/inward/record.url?scp=85030173277&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85030173277&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.96.125206

DO - 10.1103/PhysRevB.96.125206

M3 - Article

VL - 96

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 2469-9950

IS - 12

M1 - 125206

ER -