Related papers: YbRh2Si2: Quantum tricritical behavior in itineran…

Results of combined thermal and electrical transport measurements through the magnetic field-induced quantum critical point in the heavy-fermion compound YbRh2Si2 are revisited to explore the relationship between the strange-metal behavior,…

Upon application of an external tuning parameter, a magnetic state can be driven to a normal metal state at zero temperature. This phenomenon is known as quantum criticality and leads to fascinating responses in thermodynamics and transport…

For a system near a quantum critical point (QCP), above its lower critical dimension $d_L$, there is in general a critical line of second order phase transitions that separates the broken symmetry phase at finite temperatures from the…

We study the stability of the Quantum Critical Point (QCP) for itinerant ferromagnets commonly described by the Hertz-Millis-Moriya (HMM) theory. We argue that in $D \leq 3$, long-range spatial correlations associated with the Landau…

Quantum criticality near a tricritical point (TCP) is studied in the two-component Bose-Hubbard model on square lattices. The existence of quantum TCP on a boundary of superfluid-insulator transition is confirmed by quantum Monte Carlo…

We consider an inhomogeneous anisotropic gap superconductor in the vicinity of the quantum critical point, where the transition temperature is suppressed to zero by disorder. Starting with the BCS Hamiltonian, we derive the Ginzburg-Landau…

Analytical and continuous-time quantum Monte Carlo methods are used to investigate the possibility of occupation switching and quantum criticality in a model of two quantum impurities coupled to two leads. A general discussion of potential…

We report far-infrared optical properties of YbRh$_{2}$Si$_{2}$ for photon energies down to 2 meV and temperatures 0.4 -- 300 K. In the coherent heavy quasiparticle state, a linear dependence of the low-energy scattering rate on both…

We investigate the specific heat, $c$, near an Ising nematic quantum critical point (QCP), using sign problem-free quantum Monte Carlo simulations. Cooling towards the QCP, we find a broad regime of temperature where $c/T$ is close to the…

At quantum critical points (QCP) \cite{Pfeuty:1971,Young:1975,Hertz:1976,Chakravarty:1989,Millis:1993,Chubukov:1 994,Coleman:2005} there are quantum fluctuations on all length scales, from microscopic to macroscopic lengths, which,…

Quantum criticality has attracted considerable attention both theoretically and experimentally as a way to describe part of the phase diagram of strongly correlated systems. A scale-invariant fluctuation spectrum at a quantum critical point…

We study a system of two tunnel-coupled quantum dots, with the first dot containing interacting electrons (described by the Universal Hamiltonian) not subject to spin-orbit coupling, whereas the second contains non-interacting electrons…

Due to weak spin-orbit coupling, the magnetic excitations of an itinerant ferromagnet become magnetic rotons, excitations with degenerate minima on a hypersphere at finite wavevector. Using self-consistent Hartree and renormalization group…

Quantum criticality describes the collective fluctuations of matter undergoing a second-order phase transition at zero temperature. Heavy fermion metals have in recent years emerged as prototypical systems to study quantum critical points.…

This article is aimed at a pedagogical introduction to the physics of quantum phase transitions that is unique to metallic systems. It has been recognized for some time that quantum criticality can result in a breakdown of Landau's Fermi…

We discuss non-Fermi liquid and quantum critical behavior in heavy fermion materials, focussing on the mechanism by which the electron mass appears to diverge at the quantum critical point. We ask whether the basic mechanism for the…

We calculate the temperature dependence of conductivity due to interaction correction for a disordered itinerant electron system close to a ferromagnetic quantum critical point which occurs due to a spin density wave instability. In the…

Kinetic properties of a two dimensional model of fermions interacting with antiferromagnetic spin excitations near the quantum critical point (QCP) are considered. The temperature or doping are assumed to be sufficiently high, such that the…

The universality of the strange metal phase in many quantum materials is often attributed to the presence of a quantum critical point (QCP), a zero-temperature phase transition ruled by quantum fluctuations. In cuprates, where…

The electrical transport and thermoelectric properties of K_xSr_{1-x}Fe_2As_2 are investigated for 0<x<1. The resistivity rho(T) shows a crossover from Fermi liquid-like temperature dependence at small x to linear rho~T dependence at…