2017/08/31 by Francesca Finocchiaro, Franca Finocchiaro, F. Guinea +3 · 2 citations
Physics and Astronomy · #Andreev reflection #Condensed matter physics #Coupling (piping) #MAJORANA #Magnetic field #Materials science #Physics #Quantum and electron transport phenomena #Quantum many-body systems #Quantum mechanics #Quantum tunnelling #Sign (mathematics) #Superconductivity #Topological Materials and Phenomena #Topology (electrical circuits) #Zeeman effect #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.120.116801
published as Phys. Rev. Lett. 120, 116801 (2018) · 10 pages, 5 figures. Corrected minor errors, updated figures and references
openalex created_date 2017/09/15 · openalex publication_date 2018/03/15 · arxiv created 2018/03/20 · arxiv updated 2018/03/21 · openalex updated_date 2026/08/05
We consider a two-dimensional electron gas (2DEG) in the quantum Hall regime in the presence of a Zeeman field, with the Fermi level tuned to a filling factor of ν=1. We show that, in the presence of spin-orbit coupling, contacting the 2DEG with a narrow strip of an s-wave superconductor produces a topological superconducting gap along the contact as a result of crossed Andreev reflection (CAR) processes across the strip. The sign of the topological gap, controlled by the CAR amplitude, depends periodically on the Fermi wavelength and strip width and can be externally tuned. An interface between two halves of a long strip with topological gaps of opposite sign implements a robust π junction, hosting a pair of Majorana zero modes that do not split despite their overlap. We show that such a configuration can be exploited to perform protected non-Abelian tunnel-braid operations without any fine tuning.