Auto-tuning, manipulation and braiding of topological quantum bits in tapered nanowire networks

Información del proyecto

TopoTapered

Identificador del acuerdo de subvención: 101067680

DOI

10.3030/101067680

Proyecto finalizado el 7 Abril 2025

Fecha de la firma de la CE 27 Febrero 2023

Fecha de inicio 1 Agosto 2023

Fecha de finalización 31 Julio 2025

Financiado con arreglo a

• European Research Council (ERC)

Coste total

Sin datos

Aportación de la UE

€ 150 000,00

Coordinado por

WEIZMANN INSTITUTE OF SCIENCE
Israel

Periodic Reporting for period 1 - TopoTapered (Auto-tuning, manipulation and braiding of topological quantum bits in tapered nanowire networks)

Período documentado: 2023-08-01 hasta 2025-07-31

Resumen del contexto y de los objetivos generales del proyecto

The goal of the TopoTapered PoC project was to establish tapered nanowires as a viable, robust technology to auto-tune Majorana zero modes (MZMs), transport, and braid them towards quantum computation. The formation of MZMs in quasi-one dimensional semiconducting nanowires necessitates satisfying multiple conditions: The semiconductor has strong spin-orbit coupling; The chemical potential is tuned sufficiently close to the Kramer’s degeneracy throughout the topological segment (sufficiently low disorder); The induced superconducting gap is larger than the Zeeman gap opened by a properly aligned magnetic field; Spatial manipulation of the MZMs has to be adiabatic to remain in the topological groundstate. Tapered nanowires assist in achieving two of these requirements: Tapering modulates the subband quantization along the nanowires and with it the energy of the Kramer’s degeneracy such that they cross the chemical potential at segments along the nanowire without global fine tuning; Application of a global backgate results in sliding of the induced topological segments enabling continuous adiabatic transportation of the MZMs.

Trabajo realizado desde el comienzo del proyecto hasta el final del período abarcado por el informe y los principales resultados hasta la fecha

We have successfully demonstrated the advantage of tapered nanowires in tuning their spectroscopic properties. We have grown tapered nanowires with a diameter that gradually varies along the nanowire axis. We have imaged the quasi-local spectroscopy of the electronic subbands using scanning tunneling microscopy.

Avances que van más allá del estado de la técnica e impacto potencial esperado (incluida la repercusión socioeconómica y las implicaciones sociales más amplias del proyecto hasta la fecha)

The main challenge towards the implementation of our technology has remained the convincing and robust demonstration of MZMs in such hybrid semiconducting-superconducting nanowire systems, which is a prerequisite for the implementation of tapering.

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