Related papers: Self-Duality in Superconductor-Insulator Quantum P…
The superconductor to insulator or metal transition in two dimensions (2D) provides a valuable platform for studying continuous quantum phase transitions (QPTs) and critical phenomena. Distinct theoretical models, including both fermionic…
The non-Fermi-liquid properties of an ultrasmall quantum dot coupled to a lead and to a quantum box are investigated. Tuning the ratio of the tunneling amplitudes to the lead and box, we find a line of two-channel Kondo fixed points for…
The Mott insulator-to-superfluid transition exhibited by the Bose-Hubbard model on a two-dimensional square lattice occurs for any value of the chemical potential, but becomes critical at the tips of the so-called Mott lobes only. Employing…
We interpret the upper-critical-field anomalies observed in some high- temperature superconductors as resulting from the proximity to a zero-temperature quantum critical point. We estimate the shape of the phase boundary between the normal…
The angular momentum or vorticity of Cooper pairs is shown to affect strongly the charge transfer through a small superconducting (S) island of a single electron transistor. This interplay of charge and rotational degrees of freedom in a…
By using mutual flux-attaching singular gauge transformations, we derive an effective action describing the zero temperature quantum phase transition from d-wave superconductor to underdoped regime. In this effective action, quantum…
In condensed matter physics, Kramers-Wannier duality implies that the state disordered by quantum fluctuations or temperature actually corresponds with an ordered state formed from the topological excitations of the 'original' ordered…
We employ large-scale Monte Carlo simulations to study a particle-hole symmetric site-diluted quantum rotor model in two dimensions. The ground state phase diagram of this system features two distinct quantum phase transitions between the…
Quantum vorticity in polariton systems has been traditionally investigated within the frame of many-body phenomena under the mean-field or coherent approaches. In the present work, we show that the fully quantized picture describes richer…
We analyze here the behavior near the 2D insulator-superconductor quantum critical point in the presence of a perpendicular magnetic field. We show that with increasing field $H$, the quantum disordered and quantum critical regimes, in…
By using a dual vortex method, we study phases such as superfluid, solids, supersolids and quantum phase transitions in a unified scheme in extended boson Hubbard models at and slightly away from half filling on bipartite optical lattices…
We have made a variational analysis on an evolution of superconductivity from weak to strong coupling regime. In contrast to a crossover without thermodynamic anomaly found in a dilute system, we show the existence of a quantum phase…
We consider a lateral double-dot system in the Coulomb blockade regime with a single spin-1/2 on each dot, mutually coupled by an anti-ferromagnetic exchange interaction. Each of the two dots is contacted by two leads. We demonstrate that…
The gas-liquid transition is a first-order transition terminating at a finite-temperature critical point with diverging density fluctuations. Mott transition, a metal-insulator transition driven by Coulomb repulsion between electrons, has…
We investigate the effects of Coulomb interaction on charge transfer through a quantum dot attached to a normal and a superconducting lead. While for voltages much larger than the gap we recover the usual result for normal conductors, for…
Exotic physics often emerges around quantum criticality in metallic systems. Here we explore the nature of topological phase transitions between 3D double-Weyl semimetals and insulators (through annihilating double-Weyl nodes with opposite…
Kondo effect in the vicinity of a singlet-triplet transition in a vertical quantum dot is considered. This system is shown to map onto a special version of the two-impurity Kondo model. At any value of the control parameter, the system has…
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 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…
Quantum criticality is the intriguing possibility offered by the laws of quantum mechanics when the wave function of a many-particle physical system is forced to evolve continuously between two distinct, competing ground states. This…