Superconducting coherence length
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Nematic superconductivity in twisted bilayer graphene Open
Twisted bilayer graphene displays insulating and superconducting phases caused by exceptional flattening of its lowest energy bands. Superconductivity with highest Tc appears near half filling of the valence band (n≈-2). The data show that…
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Gate-Induced Interfacial Superconductivity in 1T-SnSe<sub>2</sub> Open
Layered metal chalcogenide materials provide a versatile platform to investigate emergent phenomena and two-dimensional (2D) superconductivity at/near the atomically thin limit. In particular, gate-induced interfacial superconductivity rea…
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Enhanced Cooper pairing versus suppressed phase coherence shaping the superconducting dome in coupled aluminum nanograins Open
Deterministic enhancement of the superconducting (SC) critical temperature\n$T_c$ is a long-standing goal in material science. One strategy is engineering\na material at the nanometer scale such that quantum confinement strengthens the\nel…
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Self-organized topological superconductivity in a Yu-Shiba-Rusinov chain Open
We study a chain of magnetic moments exchange coupled to a conventional three dimensional superconductor. In the normal state the chain orders into a collinear configuration, while in the superconducting phase we find that ferromagnetism i…
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Enhanced charge density wave coherence in a light-quenched, high-temperature superconductor Open
Superconductivity and charge density waves (CDWs) are competitive, yet coexisting, orders in cuprate superconductors. To understand their microscopic interdependence, a probe capable of discerning their interaction on its natural length an…
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Superconducting-like Heat Current: Effective Cancellation of Current-Dissipation Trade-Off by Quantum Coherence Open
Quantum coherence is a useful resource for increasing the speed and decreasing the irreversibility of quantum dynamics. Because of this feature, coherence is used to enhance the performance of various quantum information processing devices…
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Ultrathin two-dimensional superconductivity with strong spin–orbit coupling Open
Significance By studying epitaxially grown Pb thin films, this paper explores a new regime in the physics of uniform 2D superconductivity, in which the spin–orbit coupling-induced Rashba splitting is larger than the superconducting gap. Th…
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Fluctuation spectroscopy: From Rayleigh-Jeans waves to Abrikosov vortex clusters Open
Superconducting (SC) fluctuations, discovered in the late 1960s, have constituted an important research area in superconductivity as they are manifest in a variety of phenomena. Indeed, the underlying physics of SC fluctuations makes it po…
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Spin pumping into superconductors: A new probe of spin dynamics in a superconducting thin film Open
Spin pumping refers to the microwave-driven spin current injection from a\nferromagnet into the adjacent target material. We theoretically investigate the\nspin pumping into superconductors by fully taking account of impurity\nspin-orbit s…
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Strong-pinning regimes by spherical inclusions in anisotropic type-II superconductors Open
The current-carrying capacity of type-II superconductors is decisively determined by how well material defect structures can immobilize vortex lines. In order to gain deeper insights into intrinsic pinning mechanisms, we have explored the …
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Fermionic scenario for the destruction of superconductivity in ultrathin MoC films evidenced by STM measurements Open
We use sub-Kelvin scanning tunneling spectroscopy to investigate the suppression of superconductivity in homogeneously disordered ultrathin MoC films. We observe that the superconducting state remains spatially homogeneous even on the film…
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Propagation of superconducting coherence via chiral quantum-Hall edge channels Open
Recently, there has been significant interest in superconducting coherence via chiral quantum-Hall (QH) edge channels at an interface between a two-dimensional normal conductor and a superconductor (N–S) in a strong transverse magnetic fie…
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Anomalous metallic phase in tunable destructive superconductors Open
Multiply connected superconductors smaller than the coherence length show\ndestructive superconductivity, characterized by reentrant quantum phase\ntransitions driven by magnetic flux. We investigate the dependence of\ndestructive supercon…
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Scanning tunnelling spectroscopy of superconductivity on surfaces of LiTi2O4(111) thin films Open
Unique superconductivity at surfaces/interfaces, as exemplified by LaAlO 3 /SrTiO 3 interfaces, and the high transition temperature in ultrathin FeSe films, have triggered intense debates on how superconductivity is affected in atomic and …
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Imaging doubled shot noise in a Josephson scanning tunneling microscope Open
We have imaged the current noise with atomic resolution in a Josephson scanning tunneling microscope with a Pb-Pb junction. By measuring the current noise as a function of applied bias, we reveal the change from single-electron tunneling a…
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Proximity-induced gap in nanowires with a thin superconducting shell Open
Coupling a normal-metal wire to a superconductor induces an excitation gap Δind in the normal metal. In the absence of disorder, the induced excitation gap is strongly suppressed by finite-size effects if the thickness DS of the supercondu…
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Nonlocal superconducting correlations in graphene in the quantum Hall regime Open
We study Andreev processes and nonlocal transport in a three-terminal graphene-superconductor hybrid system under a quantizing perpendicular magnetic field [G.-H. Lee, Nat. Phys. 13, 693 (2017)1745-247310.1038/nphys4084]. We find that the …
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Ultrathin epitaxial NbN superconducting films with high upper critical field grown at low temperature Open
Ultrathin (5–50 nm) epitaxial superconducting niobium nitride (NbN) films were grown on AlN-buffered c-plane Al2O3 by an industrial scale physical vapor deposition technique at 400°C. Both X-ray diffraction and scanning electron microscopy…
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Robustness of Yu-Shiba-Rusinov resonances in the presence of a complex superconducting order parameter Open
Robust quantum systems rely on having a protective environment with minimized relaxation channels. Super-conducting gaps play an important role in the design of such environments. The interaction of localized single spins with a convention…
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Toward the Light‐Operated Superconducting Devices: Circularly Polarized Radiation Manipulates the Current‐Carrying States in Superconducting Rings Open
The ability to rapidly control and manipulate superconducting states is one of the great challenges of modern condensed matter physics. Circularly polarized radiation interacting with a superconducting condensate acts as an effective magne…
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Conductance Spectroscopy of Exfoliated Thin Flakes of Nb<sub><i>x</i></sub>Bi<sub>2</sub>Se<sub>3</sub> Open
We study unconventional superconductivity in exfoliated single crystals of a promising three-dimensional (3D) topological superconductor candidate, Nb-doped Bi2Se3 through differential conductance spectroscopy and magneto-transport. The st…
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Phase-driven collapse of the Cooper condensate in a nanosized superconductor Open
Superconductivity can be understood in terms of a phase transition from an uncorrelated electron gas to a condensate of Cooper pairs in which the relative phases of the constituent electrons are coherent over macroscopic length scales. The…
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Strong-coupling superconductivity revealed by scanning tunneling microscope in tetragonal FeS Open
We investigate the electronic properties of the tetragonal FeS superconductor by using scanning tunneling microscope/spectroscopy. It is found that the typical tunneling spectrum on the top layer of sulfur can be nicely fitted with an anis…
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Destroying Coherence in High-Temperature Superconductors with Current Flow Open
The loss of single-particle coherence going from the superconducting state to the normal state in underdoped cuprates is a dramatic effect that has yet to be understood. Here, we address this issue by performing angle resolved photoemissio…
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Controlling the electromagnetic proximity effect by tuning the mixing between superconducting and ferromagnetic order Open
The work was supported financially through the following EPSRC grants: Grants No. EP/I031014/1, No. EP/J01060X, No. EP/J010634/1, No. EP/R031924/1, No. EP/R023522/1, No. EP/L015110/1, and No. EP/L017008/1 and has received funding through t…
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Evidence for superconducting phase coherence in the metallic/insulating regime of the LaAlO<sub>3</sub>–SrTiO<sub>3</sub>interface electron system Open
A superconducting phase with an extremely low carrier density of the order of\n10^13 cm^-2 is present at LaAlO3-SrTiO3 interfaces. If depleted from charge\ncarriers by means of a gate field, this superconducting phase undergoes a\ntransiti…
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Onset of surface superconductivity beyond the Saint-James–de Gennes limit Open
We revisit the problem of the surface superconductivity nucleation focusing\non the detailed study of the critical field $H_{c3}$ as a function of\ntemperature and disorder. Using the semiclassical Eilenberger formalism we find\nthat away …
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Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe<sub>2</sub>As<sub>2</sub>Superconductors Open
Combined scanning tunneling microscopy, spectroscopy, and local barrier height (LBH) studies show that low-temperature-cleaved optimally doped Ba(Fe1-xCox)2As2 crystals with x = 0.06, with Tc = 22 K, have complicated morphologies. Although…
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Quasiparticle relaxation in superconducting nanostructures Open
We examine energy relaxation of non-equilibrium quasiparticles in "dirty" superconductors with the electron mean free path much shorter than the superconducting coherence length. Relaxation of low-energy non-equilibrium quasiparticles is d…
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Spectral properties and quantum phase transitions in superconducting junctions with a ferromagnetic link Open
We study theoretically the spectral and transport properties of a\nsuperconducting wire with a magnetic defect. We start by modelling the system\nas a one dimensional magnetic Josephson junction and derive the equation\ndetermining the ful…