Bulk disorder in the superconductor affects proximity-induced topological superconductivity

Abstract

We investigate effects of ordinary nonmagnetic disorder in the bulk of a superconductor on magnetic adatom-induced Shiba states and on the proximity-induced superconductivity in a nanowire that is tunnel coupled to the bulk superconductor. Within the formalism of self-consistent Born approximation, we show that, contrary to widespread belief, the proximity-induced topological superconductivity can be adversely affected by the bulk superconducting disorder even in the absence of any disorder in the nanowire (or the superconductor-nanowire interface) when the proximity tunnel coupling is strong. In particular, bulk disorder can effectively randomize the Shiba-state energies. In the case of a proximate semiconductor nanowire, we numerically compute the dependence of the effective disorder and pairing gap induced on the wire as a function of the semiconductor-superconductor tunnel coupling. We find that the scaling exponent of the induced disorder with respect to coupling is always larger than that of the induced gap, implying that at weak coupling, the proximity-induced pairing gap dominates, whereas at strong coupling, the induced disorder dominates. These findings bring out the importance of improving the quality of the bulk superconductor itself (in addition to the quality of the nanowire and the interface) in the experimental search for solid-state Majorana fermions in proximity-coupled hybrid structures and, in particular, points out the pitfall of pursuing strong coupling between the semiconductor and the superconductor in a goal toward having a large proximity gap. In particular, our work establishes that the bulk superconductor in strongly coupled hybrid systems for Majorana studies must be in the ultraclean limit, since otherwise the bulk disorder is likely to completely suppress all induced topological superconductivity effects.

11 pages, 8 figures

References in corpus (28)

• Non-Abelian Anyons and Topological Quantum Computation
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor
• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• Observation of Majorana Fermions in a Nb-InSb Nanowire-Nb Hybrid Quantum Device
• Majorana Zero Modes and Topological Quantum Computation
• Colloquium: Majorana Fermions in nuclear, particle and solid-state physics
• Introduction to topological superconductivity and Majorana fermions
• Anomalous modulation of a zero bias peak in a hybrid nanowire-superconductor device
• Non-Abelian quantum order in spin-orbit-coupled semiconductors: The search for topological Majorana particles in solid state systems
• Hard gap in epitaxial semiconductor-superconductor nanowires
• Interaction Effects in Topological Superconducting Wires Supporting Majorana Fermions
• Search for Majorana fermions in multiband semiconducting nanowires
• Engineering a p+ip Superconductor: Comparison of Topological Insulator and Rashba Spin-Orbit Coupled Materials
• Strong localization of Majorana end states in chains of magnetic adatoms
• Majorana Fermions and Odd-frequency Cooper Pairs in a Nano Wire
• Majorana End-States in Multi-band Microstructures with Rashba Spin-Orbit Coupling
• Topological Yu-Shiba-Rusinov chain from spin-orbit coupling
• Majorana Fermions in Chiral Topological Ferromagnetic Nanowires
• Majorana fermions in ferromagnetic chains on the surface of bulk spin-orbit coupled $s$-wave superconductors
• Interplay of topological phases in magnetic adatom-chains on top of a Rashba superconducting surface
• Topological properties of helical Shiba chains with general impurity strength and hybridization
• Bound states of a ferromagnetic wire in a superconductor
• Universal spin-triplet superconducting correlations of Majorana fermions
• Generalized Eilenberger theory for Majorana zero-mode-carrying disordered $p$-wave superconductors
• Substrate-induced Majorana renormalization in topological nanowires
• Long range $p$-wave proximity effect into a disordered metal

Cited by in corpus (37)

• Realizing Majorana zero modes in superconductor-semiconductor heterostructures
• Physical mechanisms for zero-bias conductance peaks in Majorana nanowires
• Disorder-induced zero-bias peaks in Majorana nanowires
• Effects of gate-induced electric fields on semiconductor Majorana nanowires
• Estimating disorder and its adverse effects in semiconductor Majorana nanowires
• Three-terminal nonlocal conductance in Majorana nanowires: Distinguishing topological and trivial in realistic systems with disorder and inhomogeneous potential
• Role of dissipation in realistic Majorana nanowires
• Proximity effect and Majorana bound states in clean semiconductor nanowires coupled to disordered superconductors
• Proximity-induced low-energy renormalization in hybrid semiconductor-superconductor Majorana structures
• Conductance of a superconducting Coulomb blockaded Majorana nanowire
• Finite-size effects in a nanowire strongly coupled to a thin superconducting shell
• Numerical study of PbTe-Pb hybrid nanowires for engineering Majorana zero modes
• Disorder-induced Majorana zero modes in a dimerized Kitaev superconductor chain
• Disorder effects on Majorana zero modes: Kitaev chain versus semiconductor nanowire
• Transport signatures of topological superconductivity in a proximity-coupled nanowire
• Recent progress on Majorana in semiconductor-superconductor heterostructures--Engineering and detection
• Topological superconductivity in ferromagnetic atom chains beyond the deep-impurity regime
• Disorder robustness and protection of Majorana bound states in ferromagnetic chains on conventional superconductors
• Phenomenology of soft gap, zero bias peak, and zero mode splitting in ideal Majorana nanowires
• Majorana quasiparticles of inhomogeneous Rashba chain
• How to measure the Majorana polarization of a topological planar Josephson junction
• Impurity-induced states in superconducting heterostructures
• Magnetic field effects on a nanowire with inhomogeneous Rashba spin-orbit coupling: Spin properties at equilibrium
• Enhanced topological protection in planar quasi-one-dimensional channels with periodically-modulated width
• Dimerization-induced topological superconductivity in a Rashba nanowire
• Proximity effects in cold atom artificial graphene
• Tunneling conductance in semiconductor-superconductor hybrid structures
• Electronic structure of graphene-nanoribbons on hexagonal boron nitride
• Curvature of gap closing features and the extraction of Majorana nanowire parameters
• Random matrix theory for the robustness, quantization, and end-to-end correlation of zero-bias conductance peaks in a class D ensemble
• Reveal the non-local coherent nature from a dissipative Majorana teleportation
• Topological superconductivity and anti-Shiba states in disordered chains of magnetic adatoms
• Disorder Suppression in Topological Semiconductor-Superconductor Junctions
• Topological phases in the presence of disorder and longer-range couplings
• Effects of nonmagnetic disorder on the energy of Yu-Shiba-Rusinov states
• Effects of the Vertices on the Topological Bound States in a Quasicrystalline Topological Insulator
• Proximity-induced superconductivity generated by thin films: Effects of Fermi surface mismatch and disorder in the superconductor