title: Intrinsic gap and exciton condensation in the nu{T}=1 bilayer system.
abstract: We investigate the quasiparticle excitation of the bilayer quantum Hall (QH) system at a total filling factor nu{T}=1 in the limit of negligible interlayer tunneling under a tilted magnetic field. We show that the intrinsic quasiparticle excitation is of purely pseudospin origin and solely governed by the inter- and intralayer electron interactions. A model based on exciton formation successfully explains the quantitative behavior of the quasiparticle excitation gap, demonstrating the existence of a link between the excitonic QH state and the composite fermion liquid. Our results provide a new insight into the nature of the phase transition between the two states.
authors.affiliation: NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198, Japan.
authors.forename: P
authors.initials: P
authors.lastname: Giudici
authors.forename: K
authors.initials: K
authors.lastname: Muraki
authors.forename: N
authors.initials: N
authors.lastname: Kumada
authors.forename: T
authors.initials: T
authors.lastname: Fujisawa