We propose a Josephson junction array which can be tuned into an unconventional insulating state by varying external magnetic field. This insulating state retains a gap to half-vortices; as a consequence, such an array with nontrivial global geometry exhibits a ground state degeneracy. This degeneracy is protected from the effects of external noise. We compute the gaps, separating higher energy states from the degenerate ground state, and we discuss experiments probing the unusual properties of this insulator.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.90.107003 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Exciton-polariton ring Josephson junction.
Nat Commun
January 2025
CNR Nanotec, Institute of Nanotechnology, via Monteroni, 73100, Lecce, Italy.
Macroscopic coherence in quantum fluids allows the observation of interference effects in their wavefunctions, and enables applications such as superconducting quantum interference devices based on Josephson tunneling. The Josephson effect manifests in both fermionic and bosonic systems, and has been well studied in superfluid helium and atomic Bose-Einstein condensates. In exciton-polariton condensates-that offer a path to integrated semiconductor platforms-creating weak links in ring geometries has so far remained challenging.
View Article and Find Full Text PDFJosephson diode effect in one-dimensional quantum wires connected to superconductors with mixed singlet-triplet pairing.
J Phys Condens Matter
January 2025
School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Hyderabad 500046, India.
The Josephson diode effect (JDE), characterized by asymmetric critical currents in a Josephson junction, has drawn considerable attention in the field of condensed matter physics. We investigate the conditions under which JDE can manifest in a one-dimensional Josephson junction composed of a spin-orbit-coupled quantum wire with an applied Zeeman field, connected between two superconductors (SCs). Our study reveals that while spin-orbit coupling (SOC) and a Zeeman field in the quantum wire are not sufficient to induce JDE when the SCs are purely singlet, introduction of triplet pairing in the SCs leads to the emergence of JDE.
View Article and Find Full Text PDFPseudotunnel Magnetoresistance in Twisted van der Waals FeGeTe Homojunctions.
Adv Mater
January 2025
Faculty of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Sagamihara, Kanagawa, 252-5258, Japan.
Twistronics, a novel engineering approach involving the alignment of van der Waals (vdW) integrated two-dimensional materials at specific angles, has recently attracted significant attention. Novel nontrivial phenomena have been demonstrated in twisted vdW junctions (the so-called magic angle), such as unconventional superconductivity, topological phases, and magnetism. However, there have been only few reports on integrated vdW layers with large twist angles θ, such as twisted interfacial Josephson junctions using high-temperature superconductors.
View Article and Find Full Text PDFResisting High-Energy Impact Events through Gap Engineering in Superconducting Qubit Arrays.
Phys Rev Lett
December 2024
Google Quantum AI, Santa Barbara, California 93117, USA.
Quantum error correction (QEC) provides a practical path to fault-tolerant quantum computing through scaling to large qubit numbers, assuming that physical errors are sufficiently uncorrelated in time and space. In superconducting qubit arrays, high-energy impact events can produce correlated errors, violating this key assumption. Following such an event, phonons with energy above the superconducting gap propagate throughout the device substrate, which in turn generate a temporary surge in quasiparticle (QP) density throughout the array.
View Article and Find Full Text PDFMapping the Topological Proximity-Induced Gap in Multiterminal Josephson Junctions.
Phys Rev Lett
December 2024
Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
Multiterminal Josephson junctions (MTJJs), devices in which a normal metal is in contact with three or more superconducting leads, have been proposed as artificial analogs of topological crystals. The topological nature of MTJJs manifests as a modulation of the quasiparticle density of states (DOS) in the normal metal that may be probed by tunneling measurements. We show that one can reveal this modulation by measuring the resistance of diffusive MTJJs with normal contacts, which shows rich structure as a function of the phase differences {ϕ_{i}}.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!