2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27834At 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.5 pages REVTeX, 1 .ps figure included, inset available on request from zlatko@top.physics.arizona.eduSuperconductivitytext