Phase-dependent Andreev molecules and superconducting gap closing in coherently-coupled Josephson junctions.

ABSTRACT: The Josephson junction (JJ) is an essential element of superconducting (SC) devices for both fundamental and applied physics. The short-range coherent coupling of two adjacent JJs forms Andreev molecule states (AMSs), which provide a new ingredient to engineer exotic SC phenomena such as topological SC states and Andreev qubits. Here we provide tunneling spectroscopy measurements on a device consisting of two electrically controllable planar JJs sharing a single SC electrode. We discover that Andreev spectra in the coupled JJ are highly modulated from those in the single JJs and possess phase-dependent AMS features reproduced in our numerical calculation. Notably, the SC gap closing due to the AMS formation is experimentally observed. Our results help in understanding SC transport derived

SUBMITTER: Matsuo S 

PROVIDER: S-EPMC10719386 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature