Charge transport in ferromagnetic semiconductor/s-wave superconductor junction

Abstract

We study tunneling conductance in ferromagnetic semiconductor/insulator/s-wave superconductor junction where Rashba spin-orbit interaction (RSOI) and exchange field are taken into account in the ferromagnetic semiconductor. We show that normalized conductance at zero voltage has a maximum as a function of RSOI for high transparent interface and finite exchange field. This is because Andreev reflection probability shows a nonmonotonic dependence on RSOI in the presence of the exchange field. On the other hand, for intermediate transparent interface, normalized conductance at zero voltage has a reentrant shape at zero or small exchange field with increasing RSOI but is monotonically increasing by RSOI at large exchange field.

Tunability of Andreev levels via spin-orbit coupling in Zeeman-split Josephson junctions

“…Next, we calculate the tunneling conductance σ s at zero temperature given by [32][33][34] shows it as a function of λ at zero bias voltage for various strengths of the barrier potential Z. As can be seen in the figures, the tunneling conductance is weakly affected by the RSOI, similarly to the results for two-dimensional electron gas with RSOI/superconductor junctions obtained by Yokoyama et al [33].…”

Unconventional superconductors with spin-orbit interaction

“…Next, we calculate the tunneling conductance σ s at zero temperature given by [220][221][222] shows it as a function of λ at zero bias voltage for various strengths of the barrier potential Z. As can be seen in the figures, the tunneling conductance is weakly affected by the RSOI, similarly to the results for two-dimensional electron gas with RSOI/superconductor junctions obtained by Yokoyama et.…”

Nonlocal conductance reveals helical superconductors

“…In the literature, there are two main strands of detection schemes. One direction focuses on spin transport properties [9][10][11][12], but the experimental detection of spin transport is quite difficult in general. The other direction studies the effects of the helical edge modes on local charge transport, most notably on the Andreev tunneling conductance [12,13].…”

“…One direction focuses on spin transport properties [9][10][11][12], but the experimental detection of spin transport is quite difficult in general. The other direction studies the effects of the helical edge modes on local charge transport, most notably on the Andreev tunneling conductance [12,13]. While charge transport is much easier to measure, the Andreev tunneling spectrum only indicates that there are edge states below the superconducting gap, it does not expose their helical Majorana character.…”