Current-Phase Relation of Ballistic Graphene Josephson Junctions
Gaurav Nanda,Juan L Aguilera-Servin,Juan L Aguilera-Servin,Péter Rakyta,Andor Kormányos,Reinhold Kleiner,Dieter Koelle,Kazuo Watanabe,Takashi Taniguchi,Lieven M. K. Vandersypen,Srijit Goswami +10 more
TL;DR: A fully gate-tunable graphene superconducting quantum intereference device (SQUID) is used to determine the CPR of ballistic graphene JJs and the CPR is found to be skewed, deviating significantly from a sinusoidal form.
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Abstract: The current-phase relation (CPR) of a Josephson junction (JJ) determines how the supercurrent evolves with the superconducting phase difference across the junction. Knowledge of the CPR is essential in order to understand the response of a JJ to various external parameters. Despite the rising interest in ultraclean encapsulated graphene JJs, the CPR of such junctions remains unknown. Here, we use a fully gate-tunable graphene superconducting quantum intereference device (SQUID) to determine the CPR of ballistic graphene JJs. Each of the two JJs in the SQUID is made with graphene encapsulated in hexagonal boron nitride. By independently controlling the critical current of the JJs, we can operate the SQUID either in a symmetric or asymmetric configuration. The highly asymmetric SQUID allows us to phase-bias one of the JJs and thereby directly obtain its CPR. The CPR is found to be skewed, deviating significantly from a sinusoidal form. The skewness can be tuned with the gate voltage and oscillates in antiphase with Fabry-Perot resistance oscillations of the ballistic graphene cavity. We compare our experiments with tight-binding calculations that include realistic graphene-superconductor interfaces and find a good qualitative agreement.
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Citations
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References
One-dimensional electrical contact to a two-dimensional material.
Lei Wang,Inanc Meric,Pinshane Y. Huang,Qun Gao,Yuanda Gao,Helen Tran,Takashi Taniguchi,Kenji Watanabe,Luis M. Campos,David A. Muller,Jing Guo,Philip Kim,James Hone,Kenneth L. Shepard,Cory Dean,Cory Dean +15 more
TL;DR: In graphene heterostructures, the edge-contact geometry provides new design possibilities for multilayered structures of complimentary 2D materials, and enables high electronic performance, including low-temperature ballistic transport over distances longer than 15 micrometers, and room-tem temperature mobility comparable to the theoretical phonon-scattering limit.
3.2K
The current-phase relation in Josephson junctions
TL;DR: In this article, the authors provide a theoretical basis for understanding the current phase relation (CPhiR) for the stationary Josephson effect in various types of superconducting junctions.
Electronic and magnetic properties of nanographite ribbons
TL;DR: In this paper, the magnetic properties of ribbon-shaped nanographite systems with zigzag and armchair edges in a magnetic field were investigated by using a tight-binding model.
Josephson current and noise at a superconductor/quantum-spin-Hall-insulator/superconductor junction
Liang Fu,Charles L. Kane +1 more
TL;DR: In this paper, the edge states of a quantum spin-spin-Hall insulator are modeled as a fractional Josephson effect, and the current phase relation has a constant periodicity.
Ballistic Josephson junctions in edge-contacted graphene.
V. E. Calado,Srijit Goswami,Gaurav Nanda,M. Diez,Anton R. Akhmerov,Kenji Watanabe,Takashi Taniguchi,T. M. Klapwijk,T. M. Klapwijk,Lieven M. K. Vandersypen +9 more
TL;DR: G graphene-based Josephson junctions with one-dimensional edge contacts of molybdenum rhenium are reported, finding that the critical current oscillates with the carrier density due to phase-coherent interference of the electrons and holes that carry the supercurrent caused by the formation of a Fabry-Pérot cavity.
308