Finite-momentum condensate of magnetic excitons in a bilayer quantum Hall system

• Autor(a) principal: Doretto, R. L. [UNESP]
• Data de Publicação: 2012
• Outros Autores: Morais Smith, C., Caldeira, A. O.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1103/PhysRevB.86.035326; http://hdl.handle.net/11449/226923

We study the bilayer quantum Hall system at total filling factor ν T=1 within a bosonization formalism which allows us to approximately treat the magnetic exciton as a boson. We show that in the region where the distance between the two layers is comparable to the magnetic length, the ground state of the system can be seen as a finite-momentum condensate of magnetic excitons provided that the excitation spectrum is gapped. We analyze the stability of such a phase within the Bogoliubov approximation first assuming that only one momentum Q is macroscopically occupied and later we consider the same situation for two modes ±Q. We find strong evidences that a first-order quantum phase transition at small interlayer separation takes place from a zero-momentum condensate phase, which corresponds to Halperin 111 state, to a finite-momentum condensate of magnetic excitons. © 2012 American Physical Society.