Survival of the fractional Josephson effect in time reversal invariant topological superconductors

A one-dimensional time reversal invariant topological superconductor (TRITOPS) hosts a Kramers pair of Majorana zero modes at each end. Previous work has established that TRITOPS phases do not enable rigid non-Abelian braiding, even when time-reversal symmetry is preserved throughout: local operators can mix the Majorana Kramers pair, yielding non-universal contributions to the non-Abelian Berry phase. Nonetheless, TRITOPS phases have been predicted to display other topological signatures, including a 4π periodic fractional Josephson effect. This talk will revisit the fractional Josephson effect and explore to what extent the anomalous periodicity remains robust in the presence of local mixing terms that destroy rigidity of non-Abelian braiding.