Disorder effects in planar semiconductor-superconductor structures: Majorana wires versus Josephson junctions

Abstract

Disorder effects in hybrid semiconductor-superconductor (SM-SC) nanowires, widely recognized as the main obstacle to realizing stable Majorana zero modes (MZMs) in these structures, have been systematically investigated theoretically in recent years. However, there are no corresponding detailed studies of disorder effects in planar Josephson junction (JJ) structures, which represent a promising alternative to the Majorana nanowire platform. In this paper, we perform a numerical analysis of the low-energy physics of JJ structures based on an effective microscopic model that includes two types of disorder, charge impurities inside the semiconductor and roughness on the surface of the superconducting film. We consider different parameter regimes, including low and high chemical potential values, weak and strong effective SM-SC coupling strengths, and weak and strong disorder strengths. The results are benchmarked using disordered hybrid nanowires realized in planar SM-SC structures similar to those involved in the fabrication of Josephson junctions and having similar model parameters and disorder strengths. We find that the topological superconducting phase hosted by a JJ structure is, generally, more robust against disorder than the topological superconductivity realized in a hybrid nanowire with similar parameters. On the other hand, we find that operating the JJ in a regime characterized by large values of chemical potential results in huge finite-size effects that can destroy the stability of MZMs.

27 pages, 27 figures

References in corpus (33)

• Non-Abelian Anyons and Topological Quantum Computation
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• 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 a Nb-InSb Nanowire-Nb Hybrid Quantum Device
• 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
• Scaling of Majorana Zero-Bias Conductance Peaks
• Transport spectroscopy of NS nanowire junctions with Majorana fermions
• InAs-Al Hybrid Devices Passing the Topological Gap Protocol
• SNS junctions in nanowires with spin-orbit coupling: role of confinement and helicity on the sub-gap spectrum
• Disorder-induced zero-bias peaks in Majorana nanowires
• Estimating disorder and its adverse effects in semiconductor Majorana nanowires
• Localization in disordered superconducting wires with broken spin-rotation symmetry
• Theory of Majorana zero modes in unconventional superconductors
• Signatures of a topological phase transition in a planar Josephson junction
• Tuning Topological Superconductivity in Phase-Controlled Josephson Junctions with Rashba and Dresselhaus Spin-Orbit Coupling
• Topological superconductivity in planar Josephson junctions: Narrowing down to the nanowire limit
• Phase-induced topological superconductivity in a planar heterostructure
• Partially-separated Majorana modes in a disordered medium
• Anisotropic topological superconductivity in Josephson junctions
• Spectral properties, topological patches, and effective phase diagrams of finite disordered Majorana nanowires
• Full proximity treatment of topological superconductors in Josephson-junction architectures
• Planar Josephson junctions in germanium: Effect of cubic spin-orbit interaction
• Signatures of Majorana bound states and parity effects in two-dimensional chiral p-wave Josephson junctions
• Greedy optimization of the geometry of Majorana Josephson junctions
• Random matrix theory for the robustness, quantization, and end-to-end correlation of zero-bias conductance peaks in a class D ensemble
• Phase jumps in Josephson junctions with time-dependent spin-orbit coupling
• Beyond the standard model of topological Josephson junctions: From crystalline anisotropy to finite-size and diode effects
• Disorder induced topological phase transition in a driven Majorana chain
• Stabilizing topological superconductivity in disordered spin-orbit coupled semiconductor-superconductor heterostructures

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• Planar Josephson junction devices with narrow superconducting strips: Topological properties and optimization
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