Charge impurity effects in hybrid Majorana nanowires

Abstract

We address an outstanding problem that represents a critical roadblock in the development of the Majorana-based topological qubit using semiconductor-superconductor hybrid structures: the quantitative characterization of disorder effects generated by the unintentional presence of charge impurities within the hybrid device. Given that disorder can have far-reaching consequences for the Majorana physics, but is intrinsically difficult to probe experimentally in a hybrid structure, providing a quantitative theoretical description of disorder effects becomes essential. To accomplish this task, we develop a microscopic theory that (i) provides a quantitative characterization of the effective potential generated by a charge impurity embedded inside a semiconductor wire proximity-coupled to a superconductor layer by solving self-consistently the associated three-dimensional Schrödinger-Poisson problem, (ii) describes the low-energy physics of the hybrid structure in the presence of s-wave superconductivity, spin-orbit coupling, Zeeman splitting, and disorder arising from multiple charge impurities by using the results of (i) within a standard free fermion approach, and (iii) links the microscopic results to experimentally observable features by generating tunneling differential conductance maps as function of the control parameters (e.g., Zeeman field and chemical potential). We find that charge impurities lead to serious complications regarding the realization and observation of Majorana zero modes, which have direct implications for the development of Majorana-based qubits. More importantly, our work provides a clear direction regarding what needs to be done for progress in the field, including specific materials quality and semiconductor purity targets that must be achieved to create a topological qubit.

26 pages, 31 figures

References in corpus (11)

• 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
• 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
• Transport spectroscopy of NS nanowire junctions with Majorana fermions
• Role of dissipation in realistic Majorana nanowires
• Subband occupation in semiconductor-superconductor nanowires
• Crossover between trivial zero modes in Majorana nanowires

Cited by in corpus (19)

• InAs-Al Hybrid Devices Passing the Topological Gap Protocol
• Estimating disorder and its adverse effects in semiconductor Majorana nanowires
• In search of Majorana
• Selective area epitaxy of PbTe-Pb hybrid nanowires on a lattice-matched substrate
• Numerical study of PbTe-Pb hybrid nanowires for engineering Majorana zero modes
• Local and Nonlocal Transport Spectroscopy in Planar Josephson Junctions
• Partially-separated Majorana modes in a disordered medium
• Electrostatic control of the proximity effect in the bulk of semiconductor-superconductor hybrids
• Recent progress on Majorana in semiconductor-superconductor heterostructures--Engineering and detection
• Crossover between trivial zero modes in Majorana nanowires
• Zero-frequency supercurrent susceptibility signatures of trivial and topological zero-energy states in nanowire junctions
• On-demand large-conductance in trivial zero-bias tunneling peaks in Majorana nanowires
• Observation of Aharonov-Bohm effect in PbTe nanowire networks
• Unveiling the charge distribution of a GaAs-based nanoelectronic device: A large experimental data-set approach
• Random matrix theory for the robustness, quantization, and end-to-end correlation of zero-bias conductance peaks in a class D ensemble
• Delocalized states in three-terminal superconductor-semiconductor nanowire devices
• Dephasing of Majorana qubits due to quasistatic disorder
• Electrostatics in semiconducting devices I : The Pure Electrostatics Self Consistent Approximation
• Proximity-induced superconductivity generated by thin films: Effects of Fermi surface mismatch and disorder in the superconductor