Excitonic condensation under spin-orbit coupling and BEC-BCS crossover


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HAKIOGLU T., Sahin M.

PHYSICAL REVIEW LETTERS, vol.98, no.16, 2007 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 98 Issue: 16
  • Publication Date: 2007
  • Doi Number: 10.1103/physrevlett.98.166405
  • Title of Journal : PHYSICAL REVIEW LETTERS

Abstract

The condensation of electron-hole pairs is studied at zero temperature and in the presence of a weak spin-orbit coupling (SOC) in coupled quantum wells. Under realistic conditions, a perturbative SOC can have observable effects in the order parameter of the condensate. First, the fermion exchange symmetry is absent. As a result, the condensate spin has no definite parity. Additionally, the excitonic SOC breaks the rotational symmetry yielding a complex order parameter in an unconventional way; i.e., the phase pattern of the order parameter is a function of the condensate density. This is manifested through finite off-diagonal components of the static spin susceptibility, suggesting a new experimental method to confirm an excitonic condensate.