Survival of the fractional Josephson effect in time-reversal-invariant topological superconductors
Survival of the fractional Josephson effect in time-reversal-invariant topological superconductors
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发表时间：
2020-06
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通讯作者：
Christina Knapp;Aaron Chew;J. Alicea
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作者：
Christina Knapp;Aaron Chew;J. Alicea
时间反演不变的拓扑超导体（TRITOPS）导线主机马约拉纳Kramers对已被预测调解分数约瑟夫森效应与超导相位差的周期性为4\pi $。我们探讨TRITOPS分数约瑟夫森效应中存在的时间相关的“本地混合”扰动，瞬间保持时间反演对称性。具体而言，我们表明，正如这样的耦合呈现编织的马约拉纳Kramers对非普遍的，约瑟夫森电流成为非周期性或$2\pi$周期性（取决于我们量化的条件），除非相位差扫描足够快。我们进一步分析拓扑超导体与$\mathcal{T}^2 =+1 $时间反转对称性，并揭示了丰富的相互作用和本地混合，可以在纳米线阵列实验探测之间的相互作用。
Time-reversal-invariant topological superconductor (TRITOPS) wires host Majorana Kramers pairs that have been predicted to mediate a fractional Josephson effect with $4\pi$ periodicity in the superconducting phase difference. We explore the TRITOPS fractional Josephson effect in the presence of time-dependent `local mixing' perturbations that instantaneously preserve time-reversal symmetry. Specifically, we show that just as such couplings render braiding of Majorana Kramers pairs non-universal, the Josephson current becomes either aperiodic or $2\pi$-periodic (depending on conditions that we quantify) unless the phase difference is swept sufficiently quickly. We further analyze topological superconductors with $\mathcal{T}^2 = +1$ time-reversal symmetry and reveal a rich interplay between interactions and local mixing that can be experimentally probed in nanowire arrays.