  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 and is separated from the
familiar low-field regime by a quantum level-crossing transition. Such low
energy excitations should lead to observable effects in thermodynamics and
transport.
