Work

Coupling of Klein-Andreev resonant states in B i 2 S r 2 CaC u 2 O 8 + x -graphene- B i 2 S r 2 CaC u 2 O 8 + x devices

Year: 2025

Type: article

Abstract: Quantum devices require coherent coupling over macroscopic distances. Recently, resonances due to Klein tunneling and Andreev reflection states (KARS) have been observed in a naturally occurring p-n junction at the interface between Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (BSCCO), a high-Tc superconductor (HTS), and graphene. The resonances appear as conductance oscillations with gating. Here, we show coupling between the KARS in BSCCO-graphene-BSCCO devices of varying separation (L). The coupling is evidenced by a power-law decay of resonance period as L increases from tens of nanometers to single microns. These results demonstrate the long-distance coupling of KARS cavities in graphene-HTS junctions. The length dependence seen in experiments is supported by single-particle spectral functions which show KARS are coupled by transport modes in graphene. The strong coupling between KARS in BSCCO-graphene-BSCCO junctions showcases the novelty of HTS-graphene junctions for quantum circuits and unconventional Josephson junctions.

Source: Physical review. B./Physical review. B

DOI: 10.1103/m56s-hcdq

Authors: Sharadh Jois, Jose L. Lado, Genda Gu, Qiang Li, Ji Ung Lee

Institutions: SUNY Polytechnic Institute, Aalto University, Brookhaven National Laboratory, Stony Brook University, University at Albany, State University of New York

Language: English

Topic: Physics of Superconductivity and Magnetism

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green