Related papers: Holographic quantum critical conductivity from hig…
Strongly correlated quantum fluids are phases of matter that are intrinsically quantum mechanical, and that do not have a simple description in terms of weakly interacting quasi-particles. Two systems that have recently attracted a great…
The dynamics of a two-dimensional superconductor under a constant electric field $E$ is studied by using the gauge/gravity correspondence. The pair breaking current induced by $E$ first increases to a peak value and then decreases to a…
We study high frequency response functions, notably the optical conductivity, in the vicinity of quantum critical points (QCPs) by allowing for both detuning from the critical coupling and finite temperature. We consider general dimensions…
Recent theoretical investigations have unveiled a rich structure in the quantum chromodynamics (QCD) phase diagram which consists of quark gluon plasma (QGP) and the hadronic phases but also supports the existence of a cross-over transition…
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…
Iridates provide a fertile ground to investigate correlated electrons in the presence of strong spin-orbit coupling. Bringing these systems to the proximity of a metal-insulator quantum phase transition is a challenge that must be met to…
A spin density-wave quantum critical point (QCP) is the central organizing principle of organic, iron-pnictide, heavy-fermion and electron-doped cuprate superconductors. It accounts for the superconducting Tc dome, the non-Fermi-liquid…
The electric conductivity and direct photons emission rate are considered in the holographic theory with two types of anisotropy. The electric conductivity is derived in two different ways, and their equivalence for the twice anisotropic…
We construct holographic superconductors from Einstein-Maxwell-dilaton gravity in 3+1 dimensions with two adjustable couplings $\alpha$ and the charge $q$ carried by the scalar field. For the values of $\alpha$ and $q$ we consider, there is…
Virtuality and coherence determine the limits of applicability of holographic concepts in QCD. In light-front quantization, the invariant mass controls the off-shell behavior of a physical process and thus provides a measure of its…
Electric conductivity is sensitive to effective cross sections among the particles of the partonic medium. We investigate the electric conductivity of a hot plasma of quarks and gluons, solving the relativistic Boltzmann equation. In order…
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…
The scaling of the AC conductivity in quantum critical holographic theories at finite density, finite temperature and in the presence of momentum dissipation is considered. It is shown that there is generically an intermediate window of…
Superfluid turbulence, often referred to as quantum turbulence, is a fascinating phenomenon for which a satisfactory theoretical framework is lacking. Holographic duality provides a systematic new approach to studying quantum turbulence by…
Quantum critical points (QCPs) are widely accepted as a source of a diverse set of collective quantum phases of matter. A central question is how the order parameters of phases near a QCP interact and determine the fundamental character of…
The quantum criticality of the two-lead two-channel pseudogap Anderson model is studied. Based on the non-crossing approximation, we calculate both the linear and nonlinear conductance of the model at finite temperatures with a voltage bias…
A quantum critical point (QCP) is currently being conjectured for the BaFe$_2$(As$_{1-x}$P$_x$)$_2$ system at the critical value $x_{\rm c} \approx$ 0.3. In the proximity of a QCP, all thermodynamic and transport properties are expected to…
We propose an unconventional topological quantum phase transition connecting a higher-order topological insulator (HOTI) and a featureless Mott insulator sharing the same symmetry patterns. We construct an effective theory description of…
We study a general class of holographic superconductor models via the St\"{u}ckelberg mechanism in the non-minimal derivative coupling theory in which the charged scalar field is kinetically coupling to Einstein's tensor. We explore the…
We study the finite-frequency inter-band transition peak in the optical conductivity of a heavy fermion system close to a Kondo breakdown quantum critical point, where the lattice Kondo temperature vanishes. As the system approaches the…