Topological superconducting state of lead nanowires in an external magnetic field.

Physical review letters · 2012 · Unclear · Insufficient evidence

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UnclearInsufficient evidencePaper 3179

Study snapshot

PublicationPhysical review letters · 2012

Study typeother

Reported directionUnclear

Evidence ratingInsufficient

Abstract

Superconductors with an odd number of bands crossing the Fermi energy have topologically protected Andreev states at interfaces, including Majorana states in one-dimensional geometries. We propose here that repeated indentation of a Pb tip on a Pb substrate can lead to nanowires such that the resulting superconducting system has novel topological properties. We have analyzed a number of conductance curves obtained in different nanowires, and observe, in a few cases, very peculiar dependence of the critical current on magnetic field. In these cases, the form of multiple Andreev reflections observed at finite voltages are compatible with topological superconductivity. The nanowires give a low number of 1D channels, large spin orbit coupling, and a sizable Zeeman energy, provided that the applied magnetic field is higher than the Pb bulk critical field.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeother

Effect directionunclear

PopulationNot supplied

Sample sizeNot supplied

ExposureNot supplied

Evidence strengthInsufficientConfidence: 66% · Peer reviewed: yes

Main findings

The authors analyzed conductance curves from different Pb nanowires and report that, in a few cases, the critical current shows a peculiar dependence on magnetic field. In those cases, the observed multiple Andreev reflections at finite voltages are described as compatible with topological superconductivity, under applied magnetic fields higher than the Pb bulk critical field.

Outcomes measured

critical current dependence on magnetic field
conductance curves
multiple Andreev reflections
evidence compatible with topological superconductivity (including Majorana/Andreev states)

Limitations

Number of nanowires/measurements not specified in the abstract
Findings reported only in 'a few cases', suggesting limited occurrence or reproducibility (details not provided)
Magnetic field characteristics (strength, static vs time-varying) not quantified in the abstract

View raw extracted JSON

{
  "study_type": "other",
  "exposure": {
    "band": null,
    "source": "external magnetic field",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "critical current dependence on magnetic field",
    "conductance curves",
    "multiple Andreev reflections",
    "evidence compatible with topological superconductivity (including Majorana/Andreev states)"
  ],
  "main_findings": "The authors analyzed conductance curves from different Pb nanowires and report that, in a few cases, the critical current shows a peculiar dependence on magnetic field. In those cases, the observed multiple Andreev reflections at finite voltages are described as compatible with topological superconductivity, under applied magnetic fields higher than the Pb bulk critical field.",
  "effect_direction": "unclear",
  "limitations": [
    "Number of nanowires/measurements not specified in the abstract",
    "Findings reported only in 'a few cases', suggesting limited occurrence or reproducibility (details not provided)",
    "Magnetic field characteristics (strength, static vs time-varying) not quantified in the abstract"
  ],
  "evidence_strength": "insufficient",
  "confidence": 0.66,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "lead nanowires",
    "superconductivity",
    "topological superconductivity",
    "Andreev states",
    "Majorana states",
    "critical current",
    "magnetic field",
    "multiple Andreev reflections",
    "spin-orbit coupling",
    "Zeeman energy"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1103/physrevlett.109.237003
PubMed: 23368245

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