Related papers: Alternating Superconductor--Insulator Transport Ch…
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…
We present a general introduction to the non-zero temperature dynamic and transport properties of low-dimensional systems near a quantum phase transition. Basic results are reviewed in the context of experiments on the spin-ladder…
Fundamental insight into the nature of the quantum phase transition from a superconductor to an insulator in two dimensions, or from one plateau to the next or to an insulator in quantum Hall effect, has been revealed through the study of…
Resistance in superconductors arises from the motion of vortices driven by flowing supercurrents or external electromagnetic fields and may be strongly affected by thermal or quantum fluctuations. The common expectation borne out in…
In these lectures, superconductivity in impure thin films close to the absolute zero of temperature is discussed. The behavior as function of the applied magnetic field and the amount of impurities suggests the presence of a…
In this article we study superconductor-insulator transitions within the general framework of an attractive Hubbard model. This is a well-defined model of s-wave superconductivity which permits different tuning parameters (disorder and…
We report on a temperature-induced transition from a conventional semiconductor to a two-dimensional topological insulator investigated by means of magnetotransport experiments on HgTe/CdTe quantum well structures. At low temperatures, we…
The true character of physical phenomena is thought to be reinforced as the system becomes disorder-free. In contrast, the two-dimensional (2D) superconductor is predicted to turn fragile and resistive away from the limit I -> 0, B -> 0, in…
A microscopic model is constructed which is able to describe multiple magnetic flux transitions as observed in recent ultra-low temperature tunnel experiments on an aluminum superconducting ring with normal metal - insulator -…
The work reported in my doctoral thesis is an experimental study of vortex dynamics and phase transitions in thin films of type II superconductors using scanning tunneling spectroscopy, low frequency ac susceptibility measurements and…
We carry out Monte Carlo simulations of the uniformly frustrated 3d XY model as a model for vortex line fluctuations in a high Tc superconductor. A density of vortex lines of f=1/25 is considered. We find two sharp phase transitions. The…
Numerical calculations on a mesoscopic ring of a type II superconductor in the London limit suggest that an Abrikosov vortex can be trapped in such a structure above a critical magnetic field and generate a phase shift in the…
We describe transport properties of two-dimensional arrays of low capacitance tunnel junctions, such as the current voltage characteristic and its dependence on external magnetic field and temperature. We discuss several experiments in…
Effects of electron doping on the BiS$_2$-based superconductors Sr$_{1-x}$La$_x$FBiS$_2$ ($0\le x\le 0.6$) have been investigated using the systematically synthesized polycrystals. The pristine compound is a band insulator with the BiS$_2$…
We review recent transport experiments that reveal two-threshold voltage-current characteristics, marked by a significant increase in noise between the two threshold voltages, at low electron densities in the insulating regime in…
We provide a microscopic-level derivation of earlier results showing that, in the critical vicinity of the superconductor-to-insulator transition (SIT), disorder and localization become negligible and the structure of the emergent phases is…
The complex ac conductivity of thin highly disordered InOx films was studied as a function of magnetic field through the nominal two-dimensional superconductor-insulator transition. We have resolved a significant finite-frequency superfluid…
Phase-coherent diffusive transport through mesoscopic hybrid superconductor/normal metal tunneling structures is investigated. For a N-s-S two-barrier tunneling system with bulk S and N electrodes coupled by a mesoscopic superconducting…
We study the nature of the zero-temperature phase transition between a d-wave superconductor and a Mott insulator in two dimensions. In this ``quantum confinement transition'', spin and charge are confined to form the electron in the Mott…
We analyze stability of superfluid currents in a system of strongly interacting ultra-cold atoms in an optical lattice. We show that such a system undergoes a dynamic, irreversible phase transition at a critical phase gradient that depends…