2020/04/30 by Torsten Karzig, William S. Cole, Dmitry I. Pikulin · 2 citations
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.126.057702
published as Phys. Rev. Lett. 126, 057702 (2021) · v2: 8 pages, 3 figures
arxiv created 2020/08/17 · arxiv updated 2021/02/10
Qubits based on Majorana zero modes are a promising path towards topological quantum computing. Such qubits, though, are susceptible to quasiparticle poisoning which does not have to be small by topological argument. We study the main sources of the quasiparticle poisoning relevant for realistic devices -- non-equilibrium above-gap quasiparticles and equilibrium localized subgap states. Depending on the parameters of the system and the architecture of the qubit either of these sources can dominate the qubit decoherence. However, we find in contrast to naive estimates that in moderately disordered, floating Majorana islands the quasiparticle poisoning can have timescales exceeding seconds.