Sho Nakosai

Topological superconductivity in bilayer Rashba system.

We theoretically study a possible topological superconductivity in the interacting two layers of Rashba systems, which can be fabricated by the heterostructures of semiconductors and oxides. The hybridization, which induces the gap in the single particle dispersion, and the electron-electron interaction between the two layers leads to the novel phase diagram of the superconductivity. It is found that the topological superconductivity without breaking time-reversal symmetry is realized when (i) the Fermi energy is within the hybridization gap, and (ii) the interlayer interaction is repulsive, both of which can be satisfied in realistic systems. Edge channels are studied in a tight-binding model numerically, and the several predictions on experiments are also given.

Majorana Bound States and Nonlocal Spin Correlations in a Quantum Wire on an Unconventional Superconductor

We study theoretically the proximity effect of a one-dimensional metallic quantum wire (in the absence of spin-orbit interaction) lying on top of an unconventional superconductor. Three different material classes are considered as a substrate: (i) a chiral superconductor in class D with broken time-reversal symmetry and a class DIII superconductor (ii) with and (iii) without a nontrivial Z(2) number. Interestingly, we find degenerate zero energy Majorana bound states at both ends of the wire for all three cases. They are unstable against spin-orbit interaction in case (i), while they are topologically protected by time-reversal symmetry in cases (ii) and (iii). Remarkably, we show that nonlocal spin correlations between the two ends of the wire can be simply controlled by a gate potential in our setup.

Two-dimensionalp-wave superconducting states with magnetic moments on a conventionals-wave superconductor

Unconventional superconductivity induced by the magnetic moments in a conventional spin-singlet

Spontaneous Modulation of Superconducting Phase in Kitaev Ladder

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Josephson Current of Monopolar Spinons through a Quantum Spin Ice Junction

-wave superconductor is theoretically studied. By choosing the spin directions of these moments, one can design spinless pairing states appearing within the

Skyrmion-induced bound states in a superconductor

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Skyrmion-induced Bound States in Superconductors

-wave superconducting energy gap. It is found that the helix spins produce a

Modulation of the phase in SC order parameter in Kitaev chain and its consequences

{p}_{x}+{p}_{y}

Theoretical modeling and properties of class DIII topological superconductors

-wave state while the skyrmion crystal configuration a

Topological superconducting states with magnetic moments on a conventional

{p}_{x}+i{p}_{y}