LANDAU-LEVELS AND QUASI-PARTICLE SPECTRUM OF EXTREME TYPE-II SUPERCONDUCTORS

At high magnetic fields and low temperatures, numerous extreme type-II superconductors exhibit Landau quantization of electronic motion. We present an analytic construction of the quasiparticle spectrum in this regime, based on the high-field expansion. The spectrum is gapless an d is separated from the familiar low-field regime by a quantum level-c rossing transition. Such low energy excitations should lead to observa ble effects in thermodynamics and transport.