Related papers: Destruction of superconductivity in disordered mat…
Beyond a critical disorder, two-dimensional (2D) superconductors become insulating. In this Superconductor-Insulator Transition (SIT), the nature of the insulator is still controversial. Here, we present an extensive experimental study on…
In multiorbital materials, superconductivity can exhibit new exotic forms that include several coupled condensates. In this context, quantum confinement in two-dimensional superconducting oxide interfaces offers new degrees of freedom to…
We probe the effects of strong disorder (2.4 < kFl < 8.6) on superconductivity in thin films of niobium titanium nitride and titanium nitride by measuring the microwave electrodynamics in coplanar waveguide resonators. We find a gradual…
For the first order Metal Insulator Transitions we show that together with the d.c conductance zero there is a second critical point, where the dielectric constant becomes zero and further turns negative. At this point the metallic…
Recent experiments showed that thinning gallium, iron selenide and 2H tantalum disulfide to single/several monoatomic layer(s) enhances their superconducting critical temperatures. Here, we characterize these superconductors by extracting…
BaPb$_{1-x}$Bi$_x$O$_3$ is a superconductor, with transition temperature $T_c=11$ K, whose parent compound BaBiO$_3$ possess a charge ordering phase and perovskite crystal structure reminiscent of the cuprates. The lack of magnetism…
We present in this paper the conductance maps at 100 mK in the disordered polycrystalline film of titanium nitride (TiN). At 5 nm, the film is close to quasi-two dimensional limit and exhibits features pertaining to the superconductor to…
A powerful approach to analysing quantum systems with dimensionality $d>1$ involves adding a weak coupling to an array of one-dimensional (1D) chains. The resultant quasi-one-dimensional (q1D) systems can exhibit long-range order at low…
The electrical conductivity of disordered insulator-conductor composites have been studied for more than thirty years. In spite of this some properties of dc bulk conductivity of composites still remain incompletely understood. We present a…
Rock-salt type niobium nitride ($\delta$-NbN) is a well-known superconductor having superconducting transition temperature (Tc) $\approx$ 18\,K and a large superconducting gap $\approx$3\,meV. The Tc of $\delta$-NbN thin film exhibits a…
We investigate $T_c$ and magnetic penetration depth $\lambda (T)$ near the superconductor-metal quantum phase transition in overdoped $La_{2-x}Sr_{x}CuO_{4}$ films. Both $T_c$ and superfluid density $n_s$, $\propto \lambda^{-2}$, decrease…
Using an analysis similar to that of Imry and Wortis, it is shown that the apparent first order superconductor to metal transition, which has been claimed to exist at low values of the magnetic field in a two-dimensional field-tuned system…
The phenomenon of field-induced superconductor to insulator transition (SIT) in disordered 2D electron systems has been a subject of controversy since its discovery in the early 1990s. Here we present a phenomenological quantitative theory…
Two-dimensional (2D) materials are not expected to be metals at low temperature due to electron localization. Consistent with this, pioneering studies on thin films reported only superconducting and insulating ground states, with a direct…
Motivated by a recent argument that the superconducting (SC) transition field of three-dimensional (3D) disordered superconductors with granular structure in a nonzero magnetic field should lie above $H_{c2}(0)$ in low $T$ limit, the glass…
We isolated flux disorder effects on the transport at the critical point of the quantum magnetic field tuned Superconductor to Insulator transition (BSIT). The experiments employed films patterned into geometrically disordered hexagonal…
We present measurements of $ab$-plane resistivity $\rho_{ab}(T)$ and superfluid density [$\propto \lambda^{-2}$, $\lambda$ = magnetic penetration depth] in $La_{2-x}Sr_{x}CuO_{4}$ films. As Sr concentration $x$ exceeds about 0.22, the…
Disorder effects on three-dimensional second-order topological insulators (3DSOTIs) are investigated numerically and analytically. The study is based on a tight-binding Hamiltonian for non-interacting electrons on a cubic lattice with a…
Superconductor-insulator transition (SIT) driven by disorder and transverse magnetic field has been investigated in ultrathin MoN films by means of transport measurements and scanning tunneling microscopy and spectroscopy. Upon decreasing…
The position of a field-tuned superconductor-insulator quantum transition occuring in disordered thin films is examined within the mean field approximation. Our calculation shows that the microscopic disorder-induced reduction of the…