Related papers: Critical exponent for the quantum spin Hall transi…
The use of a new method for summing divergent series makes it possible to significantly increase the accuracy of determining the critical exponents from the field theoretical renormalization group. The exponent value \nu=0.6700\pm 0.0006…
The static critical phenomenology near the Curie temperature of the re-entrant metallic alloys Au_0.81Fe_0.19, Ni_0.78Mn_0.22, Ni_0.79Mn_0.21 and amorphous a-Fe_0.98Zr_0.08 is studied using a variety of experimental techniques and methods…
We have studied Shubnikov-de Haas oscillations in a two-dimensional electron system in silicon at low electron densities. Near the metal-insulator transition, only "spin" minima of the resistance at Landau-level filling factors 2, 6, 10,…
The low-temperature resistivity of a SiGe 2-dimensional hole gas has been studied using the gate controlled carrier density as a parameter. A metal-insulator transition is seen both in the temperature and in the electric field behaviour.…
We study the phase diagram of the quantum Hall effect in four-dimensional (4D) space. Unlike in 2D, in 4D there exists a metallic as well as an insulating phase, depending on the disorder strength. The critical exponent $\nu\approx 1.2$ of…
Finding microscopic models for metallic states that exhibit quantum critical properties such as $\omega/T$ scaling is a major theoretical challenge. We calculate the local dynamical spin susceptibility $\chi(T,\omega)$ for a Hubbard model…
We propose a scaling theory of 2D metal insulator transition discovered by Kravchenko and coworkers. In this theory conductance/resistance duality is an exact relation. The exponent of the stretched exponential in $\sigma(T)$ is determined…
We study the Anderson localization in a weakly coupled multilayer system with a strong magnetic field perpendicular to the layers. The phase diagram of 1/3 flux quanta per plaquette is obtained. The phase diagram shows that a…
We study analytically the metal-insulator transition in a disordered conductor by combining the self-consistent theory of localization with the one parameter scaling theory. We provide explicit expressions of the critical exponents and the…
The quantum Hall effect in a single-layer graphene sample is studied in strong magnetic fields up to 28 T. Our measurements reveal the existence of a metal- insulator transition from filling factor $\nu=-2$ to $\nu=0$. The value of the…
Classical XY spins on a two dimensional triangular lattice with antiferromagnetic interactions are reconsidered. We find that the Kosterlitz-Thouless transition associated to the U(1) symmetry appears at a temperature 0.0020(2) below the…
We take advantage of recent improvements in the grand canonical Hybrid Monte Carlo algorithm, to perform a precision study of the single-particle gap in the hexagonal Hubbard model, with on-site electron-electron interactions. After…
Time reversal symmetric topological insulators are generically robust with respect to weak local interaction, unless symmetry breaking transitions take place. Using dynamical mean-field theory we solve an interacting model of quantum spin…
We analyze here the behavior of the Hall conductivity $\sigma_{xy}$ near a $z=2$ insulator-superconductor quantum critical point in a perpendicular magnetic field. We show that the form of the conductivity is sensitive to the presence of…
Critical thermodynamics close to a metamagnetic quantum critical endpoint (QCEP) in a metal is discussed within the framework of spin-fluctuation theory. We analyze the effective potential for the Ising order parameter that is renormalized…
A new summability method was tested to calculate the critical exponent $\nu$ of the localization length for the symplectic case derived from the non-linear $\sigma$-model. Although we used the same series as Hikami and others, unlike them…
In extensive Monte Carlo simulations the phase transition of the random field Ising model in three dimensions is investigated. The values of the critical exponents are determined via finite size scaling. For a Gaussian distribution of the…
We report a continuous phase transition between quantum-anomalous-Hall and trivial-insulator phases in a magnetic topological insulator upon magnetization rotation. The Hall conductivity transits from one plateau of quantized Hall…
We consider the spin quantum Hall transition which may occur in disordered superconductors with unbroken SU(2) spin-rotation symmetry but broken time-reversal symmetry. Using supersymmetry, we map a model for this transition onto the…
The Anderson transitions in a random magnetic field in three dimensions are investigated numerically. The critical behavior near the transition point is analyzed in detail by means of the transfer matrix method with high accuracy for…