Quasiparticle poisoning in the operating regime of topological qubits

A recent measurement reports parity switching time scales of a fermionic mode in an InAs-Al heterostructure of ~2 ms in the operating regime of topological qubits (arXiv:2401.09549). Here, we present evidence that this process is due to non-equilibrium quasiparticle poisoning and estimate the corresponding density of non-equilibrium quasiparticles. We also discuss how these densities compare to data from a Cooper pair box test device that was used to independently benchmark the measurement setup. Our results are encouraging for the estimated impact of quasiparticle poisoning on the operation of topological qubits.