Large tunable kinetic inductance in a twisted graphene superconductor

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Cryogenic systems are essential to many modern scientific and technological applications, including MRI superconducting magnets, particle accelerators, astrophysical detectors and quantum computing platforms, all of which operate at temperatures well below 120 K. In this framework, accurate temperature monitoring is, therefore, critical. However, conventional Resistance Temperature Detectors (RTDs) suffer from significant limitations in cryogenic environments, such as wiring complexity, power dissipation, l

We derive a refraction law for superconducting vortices at superconductor/normal metal (S/N) interfaces that are exposed to tilted magnetic fields. Simulations of the proximity effect confirm this law and reveal vortex trapping for low effective mass. Under transport currents, we find tilt-angle-dependent core displacements due to vortex viscosities differing across the S/N interface and characteristic voltage oscillations due to the modified vortex dynamics. Our results are important for emerging three-dim

The superconducting diode effect is a key nonreciprocal phenomenon with broad relevance for superconducting electronics. Using time-dependent Ginzburg–Landau simulations, we predict and quantify a superconducting diode effect arising solely from geometric chirality imposed on a conventional superconductor. The helical geometry and magnetic-field-induced screening currents produce inequivalent critical currents for opposite polarities. The diode efficiency reaches a maximum when one current direction first n

We report pressure-induced metallization in BaMn 2 P 2 based on resistivity measurements in a diamond anvil cell. At ambient pressure, the temperature-dependent resistivity is well described by a two-gap Arrhenius model, yielding intrinsic and extrinsic activation energies of approximately 0.2 and 0.04 eV, respectively. Angle-resolved photoemission spectroscopy (ARPES) shows no detectable spectral weight at the Fermi level within the measured momentum window. The growth of spectral weight at higher binding

Layered oxyselenides are of interest as promising mid-to high-temperature thermoelectric applications due to their tunable electrical properties and intrinsically low lattice thermal conductivity (κ). Understanding microscopic phonon mechanisms driving low-κ in these materials is essential for rational design. Here, we report a layer-differentiated phonon transport in Na 2 CoSe 2 O via solving the Wigner transport equation based on first-principles calculations, where CoSe 6 and Na 6 O octahedra dominate ac

The gatemon qubits, made of transparent superconducting-semiconducting Josephson junctions, typically have even weaker anharmonicity than the opaque AlOx-junction transmons. However, flux-frustrated gatemons can acquire a much stronger anharmonicity, originating from the interference of the higher-order harmonics of the supercurrent. Here we investigate this effect of enhanced anharmonicity in split-junction gatemon devices based on InAs-Al 2D heterostructure. We find that anharmonicity in excess of 100% ca

Magnonics is an exciting and rapidly growing field revolving around the study and manipulation of magnons, the low-lying collective excitations of magnetically ordered systems. This field has emerged in response to both fundamental physics interests and the growing demand for faster, more efficient, and more reliable signal processing and computation up to THz frequencies, i.e., beyond clock frequencies of current computer technology. Magnonic devices promise to transmit and process information in ways that

Layered van der Waals materials have emerged as a major platform for exploring novel electronic phenomena and engineering artificial heterostructures with tunable properties. Among these materials, transition metal dichalcogenides (TMDs) exhibit a wide range of correlated electronic phases, including charge density waves (CDWs) and superconductivity. In this work, we investigate the natural heterostructure compound 4Hb-TaS₂, whose distinct atomic layers display different physical properties when isolated.

The study of quantum matter has become a great part of modern physics research. Quantum criticality appears in the vicinity of a quantum critical point where there is an interplay between quantum and thermal fluctuations. In the quantum critical region, ’exotic’ phases therefore appear which might be the origin of unconventional superconductivity, for example. The study of quantum phase transitions has also many potential technological applications such as in memory storage devices or in processors for futu

The crossover from an exciton gas to an electron-hole plasma is studied in a GaN/(Al,Ga)N single quantum well by means of combined time-resolved and continuous-wave photoluminescence measurements. The two-dimensional Mott transition is found to be of continuous type and to be accompanied by a characteristic modification of the quantum well emission spectrum. Beyond the critical density, the latter is strongly influenced by band-gap renormalization and Fermi filling of continuum states. Owing to the large bi

Using a fermiology approach to the computation of the magnetic susceptibility measured by neutron scattering in hole-doped high-T-c superconductors, we estimate the effects on the incommensurate peaks caused by higher d-wave harmonics of the superconducting order parameter induced by underdoping. The input parameters for the Fermi surface and d-wave gap are taken directly from angle-resolved photoemission experiments on Bi2Sr2CaCu2O8+x (Bi2212). We find that higher d-wave harmonics lower the momentum-depend

This thesis analyzes the properties of heavily doped nanocrystalline titanium dioxide. Thin films were deposited by magnetron sputtering with either water vapor as reactive gas or a periodically interrupted oxygen supply. The samples were at the same time electrically conducting and transparent. They consisted of mixtures of rutile, anatase and amorphous phases. Titanium dioxide is chemically stable, hard, non-toxic, transparent, and inexpensive. Due to a high refractive index it is often found in optical a

Angle-resolved photoemission spectroscopy reveals very surprising strain-induced effects on the electronic band dispersion of epitaxial La2-xSrxCuO4-delta thin films. In strained films we measure a band that crosses the Fermi level (E-F) well before the Brillouin zone boundary. This is in contrast to the flat band reported in unstrained single crystals and in our unstrained films, as well as in contrast to the band flattening predicted by band structure calculations for in-plane compressive strain. In spite

A high order finite difference scheme is introduced to deal with thermo-hydraulic quench simulation in superconducting magnets, specifically in the case of cable-in-conduit conductors (CICC). Liquid helium flow in CICC is governed by the unsteady convection-diffusion conservation equations, in the low Mach number and high Reynolds number flow, region. In the past. several years many methods have been considered for quench simulation in superconducting magnets, for example, finite element, finite volume, and

We have measured two structurally similar superconducting systems, RuSr2GdCu2O8 and GdBa2Cu3O7 by means of high-resolution ac susceptibility. The real and the imaginary part of ac susceptibility of both bulk-ceramic and powdered samples have been studied down to the very small magnetic-field levels. We show that there are significant differences in the evolution of superconductivity in the two studied superconducting systems. In particular, we show that the superconducting transition in the grains in RuSr2G

Mono and multifilamentary HTS tapes exhibit non-negligible AC loss in self-field and considerably higher losses in the presence of external magnetic field. The effect of the conductor’s geometry on the AC loss has been investigated in this paper. The nonlinear electromagnetic properties of the superconducting material are expressed with a B-dependent E-J power law and are implemented in Finite Element Method commercial software. The critical current density and the power index n dependence on B are obtained

Recent photoemission evidence for non-zero gap in highly overdoped Bi2Sr2-CaCu2O8+x, along the directions in the Brillouin zone where the d-wave gap exhibits nodes, is in accordance with more conventional behavior in strongly overdoped high-T-c cuprates. This differs from underdoped regime, where departures from Fermi-liquid (FL) behavior are found. Observed non-FL linear resistivity up to similar to 1050 K in low-T-c perovskite Sr2RuO4-delta is reminiscent of cuprates and implies some similarities between

Electroceramics research is driven by technology and device applications. This growing field includes a vast number of magnetic, dielectric, ionically conducting, semiconducting, and superconducting ceramics used in domains as diverse as transportation, industrial production, power engineering, medicine and health care, consumer electronics, and communication. Al the turn of the decade, three major trends are gaining importance: Materials integration issues play an increasingly important role driven by the

We present the resistivity measurements on single crystals of Sr2RuO4-delta, grown by the flux technique. We discuss the striking, linear temperature dependence of resistivity that persists up to similar to 1050 K. The superconductivity in this system is confined below 1 K. This result suggests that the non-Fermi-liquid-alike linear temperature dependence of resistivity is not an exclusive signature of the anomalous normal stare of high-T-c cuprates but rather of layered oxides in general, especially perovs

We investigated the effects of disorder in Bi2Sr2CaCu2O8+x high temperature superconductor. We found that small defect densities already suppress the characteristic spectral signature of the superconducting state. The spectral line shape clearly reflects new excitations within the gap, as expected for defect-induced pair breaking.

Large tunable kinetic inductance in a twisted graphene superconductor

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Cryogenic Thermometry Based on Superconducting Microwave Resonators

Vortex refraction and enhanced vortex velocities at tilted superconductor-normal metal interfaces

Superconducting Diode Effect Due to Chiral Meissner Currents in a Hollow Superconducting Helix

Pressure-driven metal-insulator transition in BaMn2⁢P2 : A correlated Mn-pnictide analog of Fe-based superconductors

Phonon bunching induced strong four-phonon scattering for low lattice thermal conductivity in layered Na2CoSe2O

Strongly anharmonic flux-tunable transmon based on InAs-Al 2D heterostructure

Recent advances in magnonics

Charge density waves and transport properties of 4Hb-TaS2

Quantum critical scaling

High-temperature Mott transition in wide-band-gap semiconductor quantum wells

Influence of higher d-wave gap harmonics on the dynamical magnetic susceptibility of high-temperature superconductors

Free carriers in nanocrystalline titanium dioxide thin films

Strain and high temperature superconductivity: Unexpected results from direct electronic structure measurements in thin films

Quench simulation in superconducting cables using optimized DRP scheme

Superconducting transition in ruthenocuprate RuSr2GdCu2O8 viewed from the studies of the imaginary part of ac susceptibility

Effect of the geometry of HTS on AC loss by using finite element method simulation with B-dependent E-J power law

On some common features in high and low-Tc superconducting perovskites

Electroceramic materials

Linear resistivity from similar to 1 to 1050 K in Sr2RuO4-delta single crystals grown by the flux technique

Defect-induced changes in the spectral properties of Bi2Sr2CaCu2O8+x: Angle-resolved photoemission study