Coherence of a Magnetoexciton Condensate in a Quantum Hall Insulator

Abstract

The coherent properties of a dense ensemble of triplet cyclotron magnetoexcitons in a quantum Hall insulator near the filling factor have been studied using shear interferometry methods. It has been found that a condensate of magnetoexcitons formed at fairly low temperatures by means of nonresonant photoexcitation has a higher degree of coherence compared to the gas of uncondensed magnetoexcitons: the transverse length of coherence reaches about 10 μm. The condensate can include up to 20% of all triplet magnetoexcitons.