Excitonic codensation in quantum Hall electron-hole bilayers

Bose-Einstein condensation of excitons in bilayers has been explored increasingly over the past decade. We present an effective theory of excitonic condensate phase in electron-hole systems in the quantum Hall regime and its derivation from a microscopic Hamiltonian using mean-field analysis. We present results for the critical layer separation $d$ as a function of electron-layer filling factor $\nu_e$, hole-layer filling factor $\nu_h$, and interlayer bias voltage $\Delta_v$. We extend our analysis to singlet and triplet excitons. We point out the salient differences between these systems and the (electron-electron) quantum Hall bilayers near total filling factor $\nu=1$ which have been investigated experimentally in recent years.