Physical review. B, Condensed matter
Long-range order of two interacting anyon-gas layers of opposite statistical charge
C. A. A. de Carvalho, D. Boyanovsky
Abstract
We study aspects of long-range order in a model consisting of two interacting layers of anyon gases with opposite statistical charge. We start with bosons with a statistical interaction and second quantize the theory using an approach that uses a local and gauge-invariant order parameter. We then study this model in the Bogoliubov approximation. We explicitly compute the depletion from the condensate and gauge-invariant correlation functions. We show that the ground state is a ``weak'' condensate of charge-flux composites with ``nearly long-range order.'' The condensate becomes statistically neutral in the thermodynamic limit. It is pointed out that the ``nearly long-range order'' at zero temperature has its origins in the logarithmic infrared singularities arising from the two-dimensional Coulomb repulsion induced by the long-range statistical interaction. The quasiparticle spectrum consists of one massless mode, and a plasmon mode with a weak gap. The system is quasiordered at any nonzero temperature, but we present evidence for a finite helicity modulus.