Non-fragile superconductivity with nodes in the superconducting topological insulator CuxBi2Se3: Zeeman orbital field and non-magnetic impurities

Abstract

We study the robustness against non-magnetic impurities in the topological superconductor with point nodes, focusing on an effective model of Cu${}_x$Bi${}_2$Se${}_3$. We find that the topological superconductivity with point-nodes is not fragile against non-magnetic impurities, although the superconductivity with nodes in past studies is usually fragile. Exchanging the role of spin with the one of orbital, and vice versa, we find that in the "dual" space the topological superconductor with point-nodes is regarded as the intra-orbital spin-singlet $s$-wave one. From the viewpoint of the dual space, we deduce that the point-node state is not fragile against non-magnetic impurity, when the orbital imbalance in the normal states is small. Since the spin imbalance is induced by the Zeeman magnetic field, we shall name this key quantity for the impurity effects Zeeman "orbital" field. The numerical calculations support that the deduction is correct. If the Zeeman orbital field is small, the topological superconductivity is not fragile in dirty materials, even with nodes. Thus, the topological superconductors can not be simply regarded as one of the conventional unconventional superconductors.

arXiv comment4 pages, 4 figures. Accepted for publication in PRB Rapid Communications

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Cited by in corpus (26)

• Unconventional Superconductivity
• Pairing of j=3/2 fermions in half-Heusler superconductors
• Symmetry Protected Topological Superfluids and Superconductors --- From the Basics to ${}^3$He ---
• Nematic superconductivity in doped Bi2Se3 topological superconductors
• Superconductivity in doped Dirac semimetals
• Evidence of nodes in the order parameter of the superconducting doped topological insulator Nb${}_x$Bi${}_2$Se${}_3$ via penetration depth measurements
• Robust odd-parity superconductivity in the doped topological insulator Nb${}_x$Bi${}_2$Se${}_3$
• Generalized Anderson's theorem for superconductors derived from topological insulators
• Superconducting doped topological materials
• Robustness of unconventional $s$-wave superconducting states against disorder
• Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn${}_{1-x}$In${}_x$Te for x $\ge$ 0.10
• Crossover from impurity-controlled to granular superconductivity in (TMTSF)2ClO4
• Nematic superconductivity in Cu${}_x$Bi${}_2$Se${}_3$: The surface Andreev bound states
• Critical Temperature Enhancement of Topological Superconductors: A Dynamical Mean Field Study
• The effect of interorbital scattering on superconductivity in doped Dirac materials
• Superconductivity in Cu-doped Bi${}_2$Se${}_3$ with potential disorder
• Lifshitz transition in dirty nematic superconductor
• Nuclear magnetic relaxation rates of unconventional superconductivity in doped topological insulators
• Bound states around impurities in a superconducting bilayer
• Inverse coherence effects in nuclear magnetic relaxation rates as a sign of topological superconductivity
• Role of Hund's splitting in electronic phase competition in ${\mathrm{Pb}}_{1-x}{\mathrm{Sn}}_x\mathrm{Te}$
• Possible two-component pairings in electron-doped Bi${}_2$Se${}_3$ based on a tight-binding model
• Competing effects of Hund's splitting and symmetry-breaking perturbations on electronic order in Pb${}_{1-x}$Sn${}_x$Te
• Superconducting and normal-state anisotropy of the doped topological insulator Sr${}_{0.1}$Bi${}_2$Se${}_3$
• Sensitivity of superconducting states to the impurity location in layered materials
• Theory of low-energy behaviors in topological $s$-wave pairing superconductors