title: Local adiabatic mixing of Kramers pairs of Majorana bound states.
abstract: We consider Kramers pairs of Majorana bound states under adiabatic time evolution. This is important for the prospects of using such bound states as parity qubits. We show that local adiabatic perturbations can cause a rotation in the space spanned by the Kramers pair. Hence, the quantum information is unprotected against local perturbations, in contrast to the case of single localized Majorana bound states in systems with broken time reversal symmetry. We give an analytical and a numerical example for such a rotation, and specify sufficient conditions under which a rotation is avoided. We give a general scheme for determining when these conditions are satisfied and exemplify it with a general model of a quasi-1D time reversal symmetric topological superconductor.
authors.affiliation: Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark.
authors.forename: Konrad
authors.initials: K
authors.lastname: Wölms
authors.affiliation: Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Ady
authors.initials: A
authors.lastname: Stern
authors.affiliation: Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark.
authors.forename: Karsten
authors.initials: K
authors.lastname: Flensberg