Josephson diode effect in multichannel Rashba nanowires: role of inter-subband coupling
This study demonstrates that inter-subband coupling in multichannel Rashba nanowire Josephson junctions qualitatively alters the topological phase diagram and significantly enhances the Josephson diode effect, enabling nonreciprocal supercurrents even under Zeeman fields aligned with the spin-orbit direction—a mechanism absent in single-channel systems.