Nematic superconductivity in Cu${}_x$Bi${}_2$Se${}_3$: The surface Andreev bound states

Abstract

We study theoretically the topological surface states (TSSs) and the possible surface Andreev bound states (SABSs) of Cu${}_x$Bi${}_2$Se${}_3$ which is known to be a topological insulator at $x=0$. The superconductivity (SC) pairing of this compound is assumed to have the broken spin-rotation symmetry, similar to that of the A-phase of ${}^3$He as suggested by recent nuclear-magnetic resonance experiments. For both spheroidal and corrugated cylindrical Fermi surfaces with the hexagonal warping terms, we show that the bulk SC gap is rather anisotropic; the minimum of the gap is negligibly small as comparing to the maximum of the gap. This would make the fully-gapped pairing effectively nodal. For a clean system, our results indicate the bulk of this compound to be a topological superconductor with the SABSs appearing inside the bulk SC gap. The zero-energy SABSs which are Majorana fermions, together with the TSSs not gapped by the pairing, produce a zero-energy peak in the surface density of states (SDOS). The SABSs are expected to be stable against short-range nonmagnetic impurities, and the local SDOS is calculated around a nonmagnetic impurity. The relevance of our results to experiments is discussed.

arXiv comment11 pages, 6 figures

References in corpus (44)

• Topological Insulators with Inversion Symmetry
• Superconductivity in CuxBi2Se3 and its implications for pairing in the undoped topological insulator
• Model Hamiltonian for Topological Insulators
• Odd-Parity Topological Superconductors: Theory and Application to Cu${}_x$Bi${}_2$Se${}_3$
• Hexagonal Warping Effects in the Surface States of Topological Insulator Bi${}_2$Te${}_3$
• Topological Superconductivity in CuxBi2Se3
• Observation of topological order in a Superconducting doped topological insulator (based on the Bi2Se3 class)
• Spin-Rotation Symmetry Breaking in the Superconducting State of CuxBi2Se3
• Bulk superconducting phase with a full energy gap in the doped topological insulator Cu_xBi_2Se_3
• Thermodynamic evidence for nematic superconductivity in Cu${}_x$Bi${}_2$Se${}_3$
• Superconductivity with topological surface state in SrxBi2Se3
• Odd-parity topological superconductor with nematic order: Application to CuxBi2Se3
• Local Measurements of the Superconducting Pairing Symmetry in CuxBi2Se3
• Parity-breaking phases of spin-orbit-coupled metals with gyrotropic, ferroelectric and multipolar orders
• Rotational Symmetry Breaking in a Trigonal superconductor Nb-doped Bi2Se3
• Odd-parity superconductivity in the vicinity of inversion symmetry breaking in spin-orbit-coupled systems
• Tunneling Conductance and Surface States Transition in Superconducting Topological Insulators
• Superconductivity in the doped topological insulator Cu${}_x$Bi${}_2$Se${}_3$ under high pressure
• Evolution of the fermi surface of a doped topological insulator with carrier concentration
• Odd-parity superconductors with two-component order parameters: nematic and chiral, full gap and Majorana node
• Unconventional superconductivity in CuxBi2Se3
• Proximity induced superconductivity by Bi in topological $B{i}_{2}T{e}_{2}Se$ and $B{i}_{2}S{e}_3$ films: Evidence for a robust zero energy bound state possibly due to Majorana Fermions
• Surface spectral function in the superconducting state of a topological insulator
• Superconductivity in Tl_{0.6}Bi_{2}Te_{3} Derived from a Topological Insulator
• Topological protection, disorder, and interactions: Survival at the surface of 3D topological superconductors
• Superconductivity with two-fold symmetry in topological superconductor SrxBi2Se3
• Identification of nematic superconductivity from the upper critical field
• Absence of zero-energy surface bound states in CuxBi2Se3 via a study of Andreev reflection spectroscopy
• Dirac-Fermion-Induced Parity Mixing in Superconducting Topological Insulators
• Bulk electronic state of superconducting topological insulator
• Spin-Triplet Vortex State in the Topological Superconductor CuxBi2Se3
• Time reversal symmetry breaking superconductivity in topological materials
• Models of Superconducting Cu:Bi2Se3: single versus two-band description
• Electronic structure near an impurity and terrace on the surface of a 3-dimensional topological insulator
• Superconductivity-Induced Ferromagnetism and Weyl Superconductivity in Nb-doped Bi${}_2$Se${}_3$
• Time-reversal and rotation symmetry breaking superconductivity in Dirac materials
• Non-fragile superconductivity with nodes in the superconducting topological insulator CuxBi2Se3: Zeeman orbital field and non-magnetic impurities
• Quasi-classical theory of tunneling spectroscopy in superconducting topological insulator
• Surface transport coefficients for three-dimensional topological superconductors
• Novel anisotropic spin singlet pairings in Cu${}_x$Bi${}_2$Se${}_3$ and Bi${}_2$Te${}_3$
• Quasiclassical Treatment and Odd-parity/Triplet Correspondence in Topological Superconductors
• Surface states and local spin susceptibility in doped three-dimensional topological insulators with odd-parity superconducting pairing symmetry
• Effective low energy theory for surface Andreev bound states of superconducting phases in generalized Bernevig-Hughes-Zhang models
• Pseudospin bases for a model of Cu:Bi${}_2$Se${}_3$

Cited by in corpus (11)

• Nematic superconductivity in topological insulators induced by hexagonal warping
• Coupled Wire Models of Interacting Dirac Nodal Superconductors
• Spontaneous strain and magnetization in doped topological insulators with nematic and chiral superconductivity
• Lifshitz transition in dirty nematic superconductor
• Quasiparticle interference in doped topological insulators with nematic superconductivity
• Pauli paramagnetism of triplet Cooper pairs in a nematic superconductor
• Odd-frequency pairs and anomalous proximity effect in nematic and chiral states of superconducting topological insulators
• 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
• On the existence of nematic-superconducting states in the Ginzburg-Landau regime
• Anomalous Josephson Hall effect in doped topological insulators with the nematic superconductivity