A “squeezed-vacuum” state considered in quantum optics is shown to be realized in the ground-state wave function for the bilayer quantum Hall system at the total Landau-level filling of (Formula presented) ((Formula presented) is an odd integer). This is derived in the boson approximation, where a particle-hole pair creation across the symmetric-antisymmetric gap, (Formula presented) is regarded as a boson. In terms of the pseudospin describing the layers, the state is a spin-squeezed state, where the degree of squeezing is controlled by the layer separation and (Formula presented). An exciton condensation, which amounts to a rotated spin-squeezed state, has a higher energy due to the degraded SU(2) symmetry for (Formula presented).
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 1997|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics