Nuclear magnetic relaxation rates of unconventional superconductivity in doped topological insulators

Abstract

We study the temperature dependence of nuclear magnetic relaxation (NMR) rates to detect a sign of topological superconductivity in doped topological insulators, such as $M$($=$Cu,Nb,Sr)${}_x$Bi${}_2$Se${}_3$ and Sn${}_{1-x}$In${}_x$Te. The Hebel-Slichter coherence effect below a critical temperature Tc depends on the superconducting states predicted by a minimal model of doped topological insulators. In a nodal anisotropic topological state similar to the ABM-phase in ${}^3$He, the NMR rate has a conventional $s$-wave like coherence peak below Tc. In contrast, in a fully-gapped isotropic topological superconducting state, this rate below Tc exhibits an anti-peak profile. Moreover, in a two-fold in-plane anisotropic topological superconducting state, there is no coherence effect, which is similar to that in a chiral $p$-wave state. Thus, we reveal that the NMR rates shed light on unconventional superconductivity in doped topological insulators.

8 pages, 3 figures

References in corpus (14)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Insulators with Inversion Symmetry
• Spin-Rotation Symmetry Breaking in the Superconducting State of CuxBi2Se3
• Thermodynamic evidence for nematic superconductivity in Cu${}_x$Bi${}_2$Se${}_3$
• Odd-parity topological superconductor with nematic order: Application to CuxBi2Se3
• Direct Evidence for the Dirac-Cone Topological Surface States in Ternary Chalcogenide TlBiSe2
• Local Measurements of the Superconducting Pairing Symmetry in CuxBi2Se3
• Odd-Parity Pairing and Topological Superconductivity in a Strongly Spin-Orbit Coupled Semiconductor
• Nuclear magnetic relaxation and superfluid density in Fe-pnictide superconductors: An anisotropic \pm s-wave scenario
• Non-fragile superconductivity with nodes in the superconducting topological insulator CuxBi2Se3: Zeeman orbital field and non-magnetic impurities
• Non-magnetic impurity effects in a three-dimensional topological superconductor: From p- to s-wave behaviors
• Effect of Fermi surface evolution on superconducting gap in superconducting topological insulator
• Field-angle-dependent low-energy excitations around a vortex in the superconducting topological insulator CuxBi2Se3

Cited by in corpus (6)

• Nematic and chiral superconductivity induced by odd-parity fluctuations
• Possible structural origin of superconductivity in Sr-doped Bi2Se3
• Chiral Superconductivity in Thin Films of doped Bi${}_2$Se${}_3$
• Majorana Kramers pair in a nematic vortex
• Visualizing Pairing Symmetry in Nematic Superconductors using spin-polarized spectroscopy of magnetic impurities
• Possible two-component pairings in electron-doped Bi${}_2$Se${}_3$ based on a tight-binding model