Quasiparticles in the vortex state ofV3Si

Low-energy quasiparticle excitations in the vortex state of the superconductor ${\mathrm{V}}_3$Si have been investigated using the de Haas–van Alphen effect. Quantum oscillations persist to surprisingly low values of ${\mathit{B}}_0$/${\mathit{B}}_{\mathit{c}2}$∼0.6 and T/${\mathit{T}}_{\mathit{c}}$∼0.001. The superconducting state introduces a field-dependent quasiparticle damping which has a value ħ${\mathrm{\tau }}^{\mathrm{-}1}$≊0.25Δ at the lowest fields investigated, considerably less than the superconducting gap Δ. Quantum oscillations are attributed to the presence of a gapless excitation spectrum and may be a universal characteristic of superconductors in the vortex state.