Effect of helical edge states on the tunneling conductance in ferromagnet/noncentrosymmetric superconductors junctions

Abstract

Helical edge states exist in the mixed spin-singlet and spin-triplet phase of a noncentrosymmetric (NCS) superconductor. In this article we have considered a planar ferromagnetic metal/NCS superconductor tunnel junction and have studied the effect of these helical edge states which manifests itself through the charge and spin tunneling conductance across the junction. We have shown the behavior of conductances for the entire range of variation of $\gamma ={\Delta }_{-}/{\Delta }_{+}$ where ${\Delta }_{\pm }$ are the order parameters in the positive and negative helicity bands of the NCS superconductor.There exists a competition between the Rashba parameter $\alpha$ and the exchange energy $E_{ex}$ which is crucial for determining the variation of the conductance with the applied bias voltage across the junction. We have found a nonzero spin current across the junction which appears due to the exchange energy in the Ferromagnet and modulates with the bias voltage. It also changes its profile when the strength of the exchange energy is varied.

16 pages,4 figures,minor changes made,few references added

References in corpus (14)

• Topological Phases of Noncentrosymmetric Superconductors: Edge States, Majorana Fermions, and the Non-Abelian Statistics
• Topological spin-current in non-centrosymmetric superconductors
• Surface bound states and spin currents in non-centrosymmetric superconductors
• Andreev bound states and tunneling characteristics of a non-centrosymmetric superconductor
• A supercurrent switch in graphene $\pi$-junctions
• Andreev-Klein reflection in graphene ferromagnet-superconductor junctions
• Interplay of ferromagnetism and triplet superconductivity in a Josephson junction
• 0-$\pi$ transition in magnetic triplet superconductor Josephson junctions
• Theory of Josephson effect in unconventional superconducting junctions with diffusive barriers
• Spontaneous spin current due to triplet superconductor--ferromagnet interfaces
• Origin and control of spin currents in a magnetic triplet Josephson junction
• Tunneling conductance of ferromagnet/noncentrosymmetric superconductor junctions
• Spin analog of the controlled Josephson charge current
• Manifestation of helical edge states as zero-bias magneto-tunneling-conductance peaks in non-centrosymmetric superconductors

Cited by in corpus (3)

• Topological surface states in nodal superconductors
• Nature and symmetry of the order parameter of the noncentrosymmetric superconductor Li2Pt3B
• Theory of tunneling conductance of anomalous Rashba metal / superconductor junctions