Suppressing quasiparticle poisoning with a voltage-controlled filter

Abstract

Topological quantum computation requires parity conservation of the bound states in the extended superconducting networks in which nonequilibrium quasiparticles are often observed. Here, the authors demonstrate that a section of a nanowire with epitaxial aluminum and hard superconducting gap can prevent the quasiparticle tunneling between the two gapless regions. Such a quasiparticle filter can be used to prevent spreading of nonequilibrium quasiparticles to regions of the device that need to have conserved parity.