Conductance feature smearing and anisotropic suppression of induced superconductivity in a Majorana nanowire

Abstract

In a recent high-quality experimental work on normal metal--superconducting nanowire junctions arXiv:1807.01940 (2018), strong anisotropic suppression of induced superconductivity has been observed in tunnel conductance measurements in the presence of applied magnetic field with variable orientation. Following this finding, we investigate theoretically the dependence of tunnel conductance on the direction of the Zeeman field in order to understand the operational mechanisms and to extract effective system parameters. Second, motivated by a generic discrepancy between experiment and theory, i.e., many in-gap and above-gap conductance features predicted by theory are barely observed in experiments, we study several mechanisms possibly responsible for the suppression of the theoretically predicted conductance features (e.g., length of the nanowire, self-energy effect due to the proximity effect, finite temperature, finite dissipation, and multiband effect). One essential finding in the current work is that only by a combined understanding of both suppression mechanisms can we extract effective system parameters from the experimental data (e.g., the effective nanowire-superconductor coupling, the effective Landé $g$ factor, and the chemical potential of the semiconducting nanowire). In addition, we consider topologically trivial Andreev bound states in hybrid nanowires in the presence of potential inhomogeneities, such as external quantum dots or potential inhomogeneities inside the nanowire. We compare the anisotropic, field-dependent features induced by these nontopological Andreev bound states with the corresponding features produced by topological Majorana zero modes in pristine nanostructures, so that we can provide guidance to differentiate between the topologically trivial and nontrivial cases.

19 pages, 15 figures

References in corpus (32)

• 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 a Nb-InSb Nanowire-Nb Hybrid Quantum Device
• Majorana bound states in a coupled quantum-dot hybrid-nanowire system
• 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
• Quantized Majorana conductance
• 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
• Majorana box qubits
• Ballistic superconductivity in semiconductor nanowires
• Proximity effect at the superconductor - topological insulator interface
• Two terminal charge tunneling: Disentangling Majorana zero modes from partially separated Andreev bound states in semiconductor-superconductor heterostructures
• Quantized zero bias conductance plateau in semiconductor-superconductor heterostructures without non-Abelian Majorana zero modes
• Braiding without Braiding: Teleportation-Based Quantum Information Processing with Majorana Zero Modes
• Effects of gate-induced electric fields on semiconductor Majorana nanowires
• Decaying spectral oscillations in a Majorana wire with finite coherence length
• Hybridization at superconductor-semiconductor interfaces
• Zero bias conductance peak in Majorana wires made of semiconductor-superconductor hybrid structures
• Distinguishing topological Majorana bound states from trivial Andreev bound states: Proposed tests through differential tunneling conductance spectroscopy
• Electric field tunable superconductor-semiconductor coupling in Majorana nanowires
• Effective theory approach to the Schrodinger-Poisson problem in semiconductor Majorana devices
• Role of dissipation in realistic Majorana nanowires
• Electron temperature and tunnel coupling dependence of zero-bias and almost-zero-bias conductance peaks in Majorana nanowires
• Metamorphosis of Andreev bound states into Majorana bound states in pristine nanowires
• Conductance spectroscopy on Majorana wires and the inverse proximity effect
• Phenomenology of soft gap, zero bias peak, and zero mode splitting in ideal Majorana nanowires
• Conductance interference in a superconducting Coulomb blockaded Majorana ring

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• Parity protected superconducting diode effect in topological Josephson junctions
• Trivial Andreev band mimicking topological bulk gap reopening in the non-local conductance of long Rashba nanowires
• Microwave-Tunable Diode Effect in Asymmetric SQUIDs with Topological Josephson Junctions
• Majorana Braiding in Realistic Nanowire Y-Junctions and Tuning Forks
• Electronic properties of InAs/EuS/Al hybrid nanowires
• Crossover between trivial zero modes in Majorana nanowires
• Pinning of Andreev bound states to zero energy in two-dimensional superconductor-semiconductor Rashba heterostructures
• Prevalence of trivial zero-energy sub-gap states in non-uniform helical spin chains on the surface of superconductors
• Kitaev chain in an alternating quantum dot-Andreev bound state array
• Two types of dark solitons in a spin-orbit-coupled Fermi gas
• Josephson current via an isolated Majorana zero mode
• Spin-resolved nonlocal transport in proximitized Rashba nanowires
• Superconducting spin properties of Majorana nanowires and the associated superconducting anomalous Hall effect
• Dark Andreev States in Superconductors
• Buried Dirac points in quantum spin Hall insulators: Implications for Majorana Kramers pair-based quantum computing