English

Odd-parity superconductivity in bilayer transition metal dichalcogenides

Superconductivity 2017-09-13 v1 Mesoscale and Nanoscale Physics

Abstract

Spin-orbit coupling in transition metal dichalcogenides (TMDCs) causes spin-valley locking giving rise to unconventional optical, transport, and superconducting properties. In this paper, we propose exotic superconductivity in bilayer group-IV TMDCs by symmetry control. The sublattice-dependent hidden spin-orbit coupling arising from local inversion symmetry breaking in the crystal structure may stabilize the odd-parity superconductivity by purely ss-wave local pairing interaction. The stability of the odd-parity superconducting state depends on the bilayer stacking. The 2Hb_b stacking in MoX2_2 and WX2_2 (X =S, Se) favors the odd-parity superconductivity due to interlayer quantum interference. On the other hand, the odd-parity superconductivity is suppressed by the 2Ha_a stacking of NbSe2_2. Calculating the phase diagram of the tight-binding model derived from first principles band calculations, we conclude that the intercalated bilayer MoS2_2 and WS2_2 are candidates for a new class of odd-parity superconductors by spin-orbit coupling.

Keywords

Cite

@article{arxiv.1707.05964,
  title  = {Odd-parity superconductivity in bilayer transition metal dichalcogenides},
  author = {Yasuharu Nakamura and Youichi Yanase},
  journal= {arXiv preprint arXiv:1707.05964},
  year   = {2017}
}

Comments

To appear in Phys. Rev. B