マジックアングルツイスト二層グラフェンにおけるゲート制御可能なジョセフソンダイオード

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Updated: Feb 8, 2026

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

Published on: July 24, 2015

Alexander Rothstein^1,2, Robin Joey Dolleman¹, Lennart Klebl^3,4

¹JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany.

|February 6, 2026

Abstract:

We report low-temperature measurements of two adjacent, gate-defined Josephson junctions (JJs) in magic-angle twisted bilayer graphene (MATBG) at a moiré filling factor near ν = -2. We show that both junctions exhibit a prominent, gate-tunable Josephson diode effect, which we explain by a combination of large kinetic inductance and nonuniform supercurrent distribution. Despite their proximity, the JJs display differences in their interference patterns and different diode behaviors, underscoring that microscopic inhomogeneities such as twist angle variations shape the nonuniform supercurrent and drive the diode behavior. As a result, the nonreciprocal supercurrent can be tuned by the gate voltage, enabling tuning of the diode efficiency and even reversing the polarity at fixed magnetic fields. Our findings offer potential routes for tailoring Josephson diode performance in superconducting quantum circuits.

キーワード:

ジョセフソンダイオードジョセフソン接合マジックアングルツイスト二層グラフェン超伝導

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Optimized Fabrication Procedure for High-Quality Graphene-based Moiré Superlattice Devices

Optimized Fabrication Procedure for High-Quality Graphene-based Moiré Superlattice Devices

Published on: July 11, 2025

Development and Functionalization of Electrolyte-Gated Graphene Field-Effect Transistor for Biomarker Detection

Development and Functionalization of Electrolyte-Gated Graphene Field-Effect Transistor for Biomarker Detection

Published on: February 1, 2022

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