相关论文: Quantum criticality features in the Co doped MnSi
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…
Dynamical mean field theory is used to study the quantum critical point (QCP) in the doped Hubbard model on a square lattice. The QCP is characterized by a universal scaling form of the self energy and a spin density wave instability at an…
This paper demonstrates the anisotropic response of quantum critical fluctuations with respect to the direction of the magnetic field $B$ in Ni-doped CeCoIn$_5$ by measuring the magnetization $M$ and specific heat $C$. The results show that…
Quantum fluctuations, which result from the Heisenberg uncertainty principle, explain a number of physical observations, from the finite mass of elementary particles to the Lamb shift in hydrogen and the Casimir effect. The local violation…
We study how an inversion-breaking quantum critical point affects the ground state of a one-dimensional electronic liquid with repulsive interaction and spin-orbit coupling. We find that regardless of the interaction strength, the critical…
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…
A key actor in the conventional theory of superconductivity is the induced interaction between electrons mediated by the exchange of virtual collective fluctuations, originally phonons. Other collective modes that can play the same role,…
Coherent states provide a natural connection of quantum systems to their classical limit and are employed in various fields of physics. Here we derive general systematic expansions, with respect to quantum parameters, of expectation values…
The quantum ferromagnetic transition at zero temperature in disordered itinerant electron systems is considered. Nonmagnetic quenched disorder leads to diffusive electron dynamics that induces an effective long-range interaction between the…
Some nondifferentiable quantities (for example, the metric signature) can be the independent physical degrees of freedom. It is supposed that in quantum gravity these degrees of freedom can fluctuate. Two examples of such quantum…
Motivated by recent experiments on large quantum dots, we consider the energy spectrum in a system consisting of $N$ particles distributed among $K<N$ independent sub-systems, such that the energy of each sub-system is a quadratic function…
Doping dependence of the spin fluctuations and the electron correlations in the effective five-band Hubbard model for iron pnictides is investigated using the fluctuation-exchange approximation. For a moderate hole doping, we find a…
We give a self-consistent theory of the scale dependent effective mass enhancement m*/m of quasiparticles by 3D antiferromagnetic (AFM) spin fluctuations in the presence of disorder at an AFM quantum critical point. The coupling of…
Quantum coherence of electrons in ferromagnetic metals is difficult to assess experimentally. We report the first measurements of time-dependent universal conductance fluctuations in ferromagnetic metal (Ni$_{0.8}$Fe$_{0.2}$) nanostructures…
We present a coherent scenario for the physics of cuprate superconductors, which is based on a charge-driven inhomogeneity, i.e. the ``stripe phase''. We show that spin and charge critical fluctuations near the stripe instability of…
We investigate the transport properties of open quantum chaotic systems in the semiclassical limit. We show how the transmission spectrum, the conductance fluctuations, and their correlations are influenced by the underlying chaotic…
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…
The alternating integrable spin chain and the $RSOS(q_{1},q_{2};p)$ model in the presence of a quantum impurity are investigated. The boundary free energy due to the impurity is derived, the ratios of the corresponding $g$ functions at low…
We propose that proximity of the first-order transition manifested by the quantum tricritical point (QTCP) explains non-Fermi-liquid properties of YbRh2Si2. Here, at the QTCP, a continuous phase transition changes into first order at zero…
Recent experimental and theoretical developments in high-temperature superconductivity are reviewed, and the empirically asymmetric behavior between hole-doped and electron-doped cuprates is contrasted. A number of phenomena previously…