相关论文: Divergence of Dynamical Conductivity at Certain Pe…
A quantum phase transition is a dramatic event marked by large spatial and temporal fluctuations, where one phase of matter with its ground state and tower of excitations reorganizes into a completely different phase. We provide new insight…
We use entanglement to track the superfluid-insulator transition (SIT) in disordered fermionic superfluids described by the one-dimensional Hubbard model. Entanglement is found to have remarkable signatures of the SIT driven by i) the…
We consider the real part of the conductivity, \sigma_1(\omega), arising from classical phase fluctuations in a model for high-T_c superconductors. We show that the frequency integral of that conductivity, \int_0^\infty \sigma_1 d\omega, is…
The magnetoresistance of thin superconducting strips subject to a perpendicular magnetic field B and low temperatures T manifests a sequence of alternating superconductor-insulator transitions (SIT). We study this phenomenon within a quasi…
In a high mobility two-dimensional electron system in Si, near the critical density, $n_c=0.32\times10^{11}$cm$^{-2}$, of the apparent metal-to-insulator transition, the conductivity displays a linear temperature ($T$) dependence around the…
The direct transition from an insulator to a superconductor (SC) in Fermi systems is a problem of long-standing interest, which necessarily goes beyond the standard BCS paradigm of superconductivity as a Fermi surface instability. We…
We report new measurements of the electrical conductivity sigma of the canonical three-dimensional metal-insulator system Si:P under uniaxial stress S. The zero-temperature extrapolation of sigma(S,T -> 0) ~\S - S_c\^mu shows an…
It is well known that the metal-insulator transition in two dimensions for non-interacting fermions takes place at infinitesimal disorder. In contrast, the superconductor-to-insulator transition takes place at a finite critical disorder (on…
Strongly disordered pseudogapped superconductors are expected to display arbitrary high values of kinetic inductance close to superconductor-insulator transition (SIT) that makes them attractive for the implementation of dissipationless…
We study an electronic model of a 2D superconductor with onsite randomness using Quantum Monte Carlo simulations. The superfluid density is used to track the destruction of superconductivity in the ground state with increasing disorder. The…
We report results of transport measurements in the quantum critical regime of the disorder tuned, 2D superconductor-insulator transition (SIT) in homogeneously disordered films. We show that, as the superconducting transition temperature…
We study the effect of morphology on the low temperature behavior of superconducting nanowires of length $\approx$100 nm. A well-defined superconductor-insulator transition (SIT) is observed only in homogenous wires, in which case the…
Utilizing a novel and exact inversion scheme, we determine the complex linear conductivity $\sigma (\omega )$ from the linear magnetic ac-susceptibility which has been measured from 3\,mHz to 50\,MHz in fields between 0.4\,T and 4\,T…
We show that the doping-controlled superconductor-insulator transition (SIT) in a high critical temperature cuprate system (Bi2Sr2-xLaxCaCu2O8+delta) exhibits a fundamentally different behavior than is expected from conventional SIT. At the…
We develop a full microscopic theory for the optical conductivity, $\sigma(\omega)$, of a dirty current-carrying superconductor. Within the Keldysh sigma model formalism, we obtain the general analytical expression for $\sigma(\omega)$,…
We analyze critical behavior of superfluid density $\rho_s$ in strongly disordered superconductors near superconductor-insulator transition and compare it with the behavior of the spectral gap $\Delta$ for collective excitations. We show…
We use ionic liquid-assisted electric field effect to tune the carrier density in an electron-doped cuprate ultrathin film and cause a two-dimensional superconductor-insulator transition (SIT). The low upper critical field in this system…
We measure the complex impedance between source/drain electrodes and the gate electrode of a pentacene thin-film transistor (TFT) at frequencies 50 Hz < omega/2pi < 20 kHz. Modeling the TFT as a distributed RC network (RC transmission…
The superconductor-to-insulator transition (SIT) induced by means such as external magnetic fields, disorder or spatial confinement is a vivid illustration of a quantum phase transition dramatically affecting the superconducting order…
Disordered thin films close to the superconducting-insulating phase transition (SIT) hold the key to understanding quantum phase transition in strongly correlated materials. The SIT is governed by superconducting quantum fluctuations, which…