相关论文: Fermions and Bosons in Superconducting Amorphous W…
The microscopic nature of an insulating state in the vicinity of a superconducting state, in the presence of disorder, is a hotly debated question. While the simplest scenario proposes that Coulomb interactions destroy the Cooper pairs at…
Electron-boson coupling plays a key role in superconductivity for many systems. However, in copper-based high-temperature ($T_c$) superconductors, its relation to superconductivity remains controversial despite strong spectroscopic…
A long one-dimensional wire with a finite density of strong random impurities is modelled as a chain of weakly coupled quantum dots. At low temperature T and applied voltage V its resistance is limited by "breaks": randomly occuring…
We study the effects of quantum fluctuations on the transport properties of multiband superconductors near a pair-breaking quantum critical point. For this purpose, we consider a minimal model of the quantum phase transition in a system…
Using the micro-canonical picture of transport -- a framework ideally suited to describe the dynamics of closed quantum systems such as ultra-cold atom experiments -- we show that the exact dynamics of non-interacting fermions and bosons…
Near a quantum-critical point in a metal a strong fermion-fermion interaction, mediated by a soft boson, destroys fermionic coherence and also gives rise to superconductivity. In a class of large $N$ models, one would naively expect an…
We study the interplay between antiferromagnetism and superconductivity in a generalized infinite-$U$ Anderson lattice, where both superconductivity and antiferromagnetic order are introduced phenomenologically in mean field theory. In a…
The criteria for bosonization of Cooper pairs and novel Bose-liquid superconductivity and superfluidity in high-$T_c$ cuprates and other pseudogap matters are formulated by using the uncertainty principle and the boson mean field theory. We…
We present self-consistent numerical calculations of the electronic structure of parallel Coulomb-confined quantum wires, based on the Hohenberg-Kohn-Sham density functional theory of inhomogeneous electron systems. We find that the…
In this article we shortly review previous and recently published experimental results that provide evidence for intrinsic, magnetic-impurity-free ferromagnetism and for high-temperature superconductivity in carbon-based materials. The…
It is natural for a Mott antiferromagnetism in RVB description to become a superconductor in doped metallic regime. But the issue of superconducting transition temperature is highly nontrivial, as the AF fluctuations in the form of RVB…
The influence of substitutional disorder on the transport properties of heavy-fermion systems is investigated. We extend the dynamical mean-field theory treatment of the periodic Anderson model (PAM) to a coherent-potential approximation…
We describe the collapse of the bosonic component in a boson-fermion mixture due to the pressure exerted on them by a large fermionic component, leading to collapse in a system with all-repulsive interactions. We describe the phenomena…
We derive the theory of the quantum (zero temperature) superconductor to metal transition in disordered materials when the resistance of the normal metal near criticality is small compared to the quantum of resistivity. This can occur most…
The conductance at the band edges of one-dimensional fermionic wires, with $N$ sites, has been shown to have subdiffusive $(1/N^2)$ behavior. We investigate this issue in two-dimensional fermionic wires described by a hopping model on an…
We quantitatively discuss the influence of quenched disorder on the ferromagnetic quantum phase transition in metals, using a theory that describes the coupling of the magnetization to gapless fermionic excitations. In clean systems, the…
The aim of this thesis is to systematically and consistently study strongly coupled bosonic and fermionic conformal field theories using the large quantum number expansion. The idea behind it is to study sectors of conformal field theories…
In these lecture notes we will consider systems in which the motion of electrons is confined to one dimension (1D). In these so-called quantum wires electron-electron interaction effects play an important role because the restricted…
We present a microscopic study of the behavior of the order parameters near boundaries of a two-band superconducting material, described by the standard tight-binding Bardeen-Cooper-Schrieffer model. We find superconducting surface states.…
We propose that a pseudospin ferromagnetic (i.e inter-wire coherent) state can exist in a system of two parallel wires of finite width in the presence of a perpendicular magnetic field. This novel quantum many-body state appears when the…