Trivial Andreev Band Mimicking Topological Bulk Gap Reopening in the Nonlocal Conductance of Long Rashba Nanowires

Emerging quantum hybrid systems for non-Abelian-state manipulation

“…For instance, in the case of the Rashba nanowire hybrid setup, while the topological gap protocol establishes some guidelines, it is still completely based on linearresponse transport spectroscopy. Particularly, the disorders can play an unexpectedly important role in suppressing the non-local signals and potentially make false-positive signals with the combination of trivial ABS ( (Hess et al, 2023a) and the discussions (Hess et al, 2023b;Sarma and Pan, 2023)). Going beyond conductance spectroscopy might settle for more stringent conditions that could bypass some of the issues caused by local defects and the resulting false positives.…”

Zeeman- and Orbital-Driven Phase Shifts in Planar Josephson Junctions

“…While zero-energy states emerging after gap reopening were robust to changes in gate voltage, consistent with a topological phase, 30 , 31 simulations have shown that these signatures could also have trivial origins. 57 , 58 Supercurrent measurements in superconducting quantum interference devices (SQUIDs) demonstrated gate-tunable phase shifts in small magnetic fields, 41 as well as large phase jumps at larger fields 34 accompanied by a minimum in the supercurrent amplitude, also consistent with a topological transition. 30 However, several questions remain on the behavior of planar JJs subjected to in-plane magnetic fields.…”

“…For instance, ref 41 reported anomalous phase shifts at small magnetic fields which were considerably larger than theoretical expectations. 44 Additionally, orbital effects can resemble the behavior expected from a topological transition: 30,58 a magnetic flux threading the cross-section underneath the superconducting leads can produce non-monotonic switching currents 32,59 together with closure and reopening of the induced superconducting gap. In this context, it is crucial to understand the mechanisms underlying phase shifts in planar JJs in an in-plane magnetic field to fully harness their properties in quantum computation and superconducting electronics applications.…”