Quantized zero-bias conductance plateau in semiconductor-superconductor heterostructures without topological Majorana zero modes

  title={Quantized zero-bias conductance plateau in semiconductor-superconductor heterostructures without topological Majorana zero modes},
  author={Christopher Moore and Chuanchang Zeng and Tudor D Stanescu and Sumanta Tewari},
  journal={Physical Review B},
We show that partially separated Andreev bound states (ps-ABSs), comprised of pairs of overlapping Majorana bound states (MBSs) emerging in quantum dot-semiconductor-superconductor heterostructures, produce robust zero bias conductance plateaus in end-of-wire charge tunneling experiments. These plateaus remain quantized at $2e^2/h$ over large ranges of experimental control parameters. In light of recent experiments reporting the observation of robust $2e^2/h$-quantized conductance plateaus in… 

Figures from this paper

Quantized and unquantized zero-bias tunneling conductance peaks in Majorana nanowires: Conductance below and above 2e2/h
Majorana zero modes can appear at the wire ends of a 1D topological superconductor and manifest themselves as a quantized zero-bias conductance peak in the tunneling spectroscopy of
Non-Majorana states yield nearly quantized conductance in superconductor-semiconductor nanowire devices
Conductance at zero source-drain voltage bias in InSb nanowire/NbTiN superconductor devices exhibits peaks that are close to a quantized value of $2e^2/h$. The nearly quantized resonances evolve in
Zero-bias conductance peak in Dirac semimetal-superconductor devices
Majorana zero modes (MZMs), fundamental building blocks for realizing topological quantum computers, can appear at the interface between a superconductor and a topological material. One of the
Reproducing topological properties with quasi-Majorana states
Andreev bound states in hybrid superconductor-semiconductor devices can have near-zero energy in the topologically trivial regime as long as the confinement potential is sufficiently smooth. These
Nearly quantized conductance plateau of vortex zero mode in an iron-based superconductor
Observations of conductance plateaus as a function of tunnel coupling for zero-energy vortex bound states with values close to or even reaching the 2e2/h quantum conductance are reported.
Robust low-energy Andreev bound states in semiconductor-superconductor structures: Importance of partial separation of component Majorana bound states
Robust topologically-trivial low-energy Andreev bound states (ABSs) induced by position-dependent effective potentials have recently come under renewed focus in light of a remarkable set of recent
Generic quantized zero-bias conductance peaks in superconductor-semiconductor hybrid structures
We show theoretically that quantized zero-bias conductance peaks should be ubiquitous in superconductor-semiconductor hybrids by employing a zero-dimensional random matrix model with continuous
From Andreev to Majorana bound states in hybrid superconductor–semiconductor nanowires
Inhomogeneous superconductors can host electronic excitations, known as Andreev bound states (ABSs), below the superconducting energy gap. With the advent of topological superconductivity, a new kind
Hybridization energy oscillations of Majorana and Andreev bound states in semiconductor-superconductor nanowire heterostructures
The recent experimental observations of decaying energy oscillations with increasing magnetic field in semiconductor-superconductor Majorana nanowires is in contrast with the theoretical expectations
Majorana versus Andreev bound state energy oscillations in a 1D semiconductor-superconductor heterostructure
The recent experimental observations of decaying energy oscillations in semiconductor-superconductor Majorana nanowires is in contrast with the typical expectations based on the presence of Majorana


Quantized Majorana conductance
The observation of a quantized conductance plateau at 2e2/h in the zero-bias conductance measured in indium antimonide semiconductor nanowires covered with an aluminium superconducting shell strongly supports the existence of Majorana zero-modes in the system.
Zero-bias peaks in the tunneling conductance of spin-orbit-coupled superconducting wires with and without Majorana end-states.
It is shown that this system generically exhibits a (nonquantized) zero-bias peak even when the wire is topologically trivial and does not possess Majorana end states, by simulating the tunneling conductance for multiband wires with realistic amounts of disorder.
Andreev bound states versus Majorana bound states in quantum dot-nanowire-superconductor hybrid structures: Trivial versus topological zero-bias conductance peaks
Motivated by an important recent experiment [Deng , Science 354, 1557 (2016)SCIEAS0036-807510.1126/science.aaf3961], we theoretically consider the interplay between Andreev and Majorana bound states
Two-terminal charge tunneling: Disentangling Majorana zero modes from partially separated Andreev bound states in semiconductor-superconductor heterostructures
We show that a pair of overlapping Majorana bound states (MBSs) forming a partially separated Andreev bound state (ps-ABS) represents a generic low-energy feature in spin-orbit-coupled
Topologically trivial zero-bias conductance peak in semiconductor Majorana wires from boundary effects
We show that a topologically trivial zero bias conductance peak (of height 4e^2/h) is produced in semiconductor-superconductor hybrid nanowires due to a suppressed pair potential and/or an excess
Majorana bound states from exceptional points in non-topological superconductors
It is shown that MDSs exhibit the full range of properties associated to conventional closed-system Majorana bound states (zero-energy, self-conjugation, 4π-Josephson effect and non-Abelian braiding statistics), while not requiring topological superconductivity.
Mutation of Andreev into Majorana bound states in long superconductor-normal and superconductor-normal-superconductor junctions
We study one-dimensional topological superconductor-normal (SN) and superconductor-normal-superconductor (SNS) long junctions obtained by placing a topological insulating nanowire in the proximity of
Exponential protection of zero modes in Majorana islands
The results help to explain the trivial-to-topological transition in finite systems and to quantify the scaling of topological protection with end-mode separation.
Observation of the fractional ac Josephson effect: the signature of Majorana particles
Topological superconductors which support Majorana fermions are thought to be realized in one-dimensional semiconducting wires coupled to a superconductor [1–3]. Such excitations are expected to
Observation of Majorana Fermions in a Nb-InSb Nanowire-Nb Hybrid Quantum Device
We report on the observation of excitation of Majorana fermions in a Nb-InSb nanowire quantum dot-Nb hybrid system. The InSb nanowire quantum dot is formed between the two Nb contacts by weak