Stacking two-dimensional van der Waals (vdW) materials rotated with respect to each other show versatility for studying exotic quantum phenomena. In particular, anisotropic layered materials have great potential for such twistronics applications, providing high tunability. Here, we report anisotropic superconducting order parameters in twisted BiSrCaCuO (Bi-2212) vdW junctions with an atomically clean vdW interface, achieved using the microcleave-and-stack technique. The vdW junctions with twist angles of 0° and 90° showed the maximum Josephson coupling, comparable to that of intrinsic Josephson junctions. As the twist angle approaches 45°, Josephson coupling is suppressed, and eventually disappears at 45°. The observed twist angle dependence of the Josephson coupling can be explained quantitatively by theoretical calculation with the -wave superconducting order parameter of Bi-2212 and finite tunneling incoherence of the junction. Our results revealed the anisotropic nature of Bi-2212 and provided a novel fabrication technique for vdW-based twistronics platforms compatible with air-sensitive vdW materials.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.nanolett.1c03906 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Dynamical Exciton Condensates in Biased Electron-Hole Bilayers.
Phys Rev Lett
November 2024
Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, USA.
Bilayer materials may support interlayer excitons comprised of electrons in one layer and holes in the other. In experiments, a nonzero exciton density is typically sustained by a bias chemical potential, implemented either by optical pumping or by electrical contacts connected to the two layers. We show that if charge can tunnel between the layers, the chemical potential bias means that an exciton condensate is in the dynamical regime of ac Josephson effect.
View Article and Find Full Text PDFEngineering Superconducting Contacts Transparent to a Bipolar Graphene.
Nano Lett
December 2024
Department of Physics, Pohang University of Science and Technology, Pohang 37673, Republic of Korea.
Graphene's exceptional electronic mobility, gate-tunability, and contact transparency with superconducting materials make it ideal for exploring the superconducting proximity effect. However, the work function difference between graphene and superconductors causes unavoidable doping of graphene near contacts, forming a p-n junction in the hole-doped regime and reducing the contact transparency. This challenges the device implementation that exploits graphene's bipolarity.
View Article and Find Full Text PDFMeasuring topological invariants for higher-order exceptional points in quantum three-mode systems.
Nat Commun
November 2024
Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, China.
Owing to the presence of exceptional points (EPs), non-Hermitian (NH) systems can display intriguing topological phenomena without Hermitian analogs. However, experimental characterizations of exceptional topological invariants have been restricted to second-order EPs (EP2s) in classical or semiclassical systems. We here propose an NH multi-mode system with higher-order EPs, each of which is underlain by a multifold-degenerate multipartite entangled eigenstate.
View Article and Find Full Text PDFDNA Gene's Basic Structure as a Nonperturbative Circuit Quantum Electrodynamics: Is RNA Polymerase II the Quantum Bus of Transcription?
Curr Issues Mol Biol
October 2024
Research and Higher Education Center of UNEPROP, Hermosillo 83105, Mexico.
Previously, we described that Adenine, Thymine, Cytosine, and Guanine nucleobases were superconductors in a quantum superposition of phases on each side of the central hydrogen bond acting as a Josephson Junction. Genomic DNA has two strands wrapped helically around one another, but during transcription, they are separated by the RNA polymerase II to form a molecular condensate called the transcription bubble. Successive steps involve the bubble translocation along the gene body.
View Article and Find Full Text PDFTwo-Dimensional Superconductivity and Anomalous Vortex Dissipation in Newly Discovered Transition Metal Dichalcogenide-Based Superlattices.
J Am Chem Soc
December 2024
Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
Properties of layered superconductors can vary drastically when thinned down from bulk to monolayer owing to the reduced dimensionality and weakened interlayer coupling. In transition metal dichalcogenides (TMDs), the inherent symmetry breaking effect in atomically thin crystals prompts novel states of matter such as Ising superconductivity with an extraordinary in-plane upper critical field. Here, we demonstrate that two-dimensional (2D) superconductivity resembling those in atomic layers but with more fascinating behaviors can be realized in the bulk crystals of two new TMD-based superconductors BaClTaS and BaClTaSe with superconducting transition temperatures 2.
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!