Long-lived magnetoexcitons and two-dimensional magnetofermionic condensate in GaAs/AlGaAs heterostructure

Excitation of long-lived triplet magnetoexcitons in a Hall insulator (filling factor $\nu$ = 2) with a high mobility of electrons, at low temperatures, $T<1$ K, enabled to discover a new collective state – magnetofermionic condensate, that interacts coherently with an external electromagnetic field, exhibits superradiant properties and, owing to its low viscosity, spreads over the surface of the two-dimensional structure for macroscopically large distances.