Selective equal spin Andreev reflection at vortex core center in magnetic semiconductor-superconductor...

Area of Science:

• Condensed Matter Physics
• Topological Materials
• Superconductivity

Background:

• The Sau, Lutchyn, Tewari, and Das Sarma (SLTD) model proposes a heterostructure for Majorana zero modes.
• Understanding spin properties in such systems is crucial for topological quantum computing.

Purpose of the Study:

• To investigate spin polarization of vortex core states.
• To analyze spin-selective Andreev reflection at the vortex center in the SLTD model.

Main Methods:

• Theoretical analysis of the SLTD heterostructure model.
• Examination of differential conductance at zero bias.
• Study of spin-orbit coupling (SOC) effects.

Main Results:

• In the topological phase, Andreev reflection at the vortex center is spin-selective with quantized differential conductance at zero bias.
• In the topological trivial phase, spin selectivity arises from SOC, with suppressed conductance in the Giaever limit.
• Conductance vanishes at zero bias in the trivial phase due to quantum interference.

Conclusions:

• The SLTD model exhibits distinct spin-selective phenomena in topological and trivial phases.
• Spin-orbit coupling plays a key role in spin selectivity in the trivial phase.
• The findings contribute to the understanding of Majorana zero modes and spin physics in topological heterostructures.