Related papers: Phase boundary near a magnetic percolation transit…
We report the magnetic and calorimetric measurements in single crystal samples of the square lattice $J_{1}-J_{2}$ quantum antiferromagnet BaCdVO(PO$_4$)$_2$. An investigation of the scaling of magnetization reveals a "dimensionality…
The square-lattice Ising antiferromagnet subjected to the imaginary magnetic field $H=i \theta T /2 $ with the "topological" angle $\theta$ and temperature $T$ was investigated by means of the transfer-matrix method. Here, as a probe to…
The applied magnetic field and temperature phase diagram of the archetypal frustrated magnet, Gd3Ga5O12, has been reinvestigated using single crystal magnetometry and polarised neutron diffraction. The updated phase diagram is substantially…
We present the results of the Monte-Carlo simulation of graphene-like statistical model in terms of occupation numbers. We study the problem of the phase transition in graphene to an insulating phase. Only antiferromagnetic order parameter…
The possibility of topological phase transition with or without a magnetic flux trapped in the cells of a class of decorated lattices is explored in details.Using a tight binding Hamiltonian and a real space decimation scheme we…
The antiferromagnetic Heisenberg model on a pyrochlore lattice under external magnetic field is studied by classical Monte Carlo simulation. The model includes bilinear and biquadratic interactions; the latter effectively describes the…
More than a quarter century after the discovery of the high temperature superconductor (HTS) YBa$_2$Cu$_3$O$_{6+\delta}$ (YBCO) studies continue to uncover complexity in its phase diagram. In addition to HTS and the pseudogap there is…
The one-dimensional attractive lattice fermion gas equivalent to the Heisenberg-Ising spin 1/2 chain is studied for a ring geometry threaded by magnetic flux. We find that for charged fermions having interaction strength $\Delta=\cos(\pi /…
In this work a site diluted antiferromagntic Ising model in the FCC lattice is studied by Monte Carlo simulation. At low temperatures, we find that as the external field is increased the transition from the antiferromagnetic phase to the…
We study the ferromagnetic phase transition in a randomly layered Heisenberg magnet using large-scale Monte-Carlo simulations. Our results provide numerical evidence for the infinite-randomness scenario recently predicted within a…
Low temperature magnetization M measurements down to 70~mK have been performed through the superconducting upper critical field H_c2 of CeCoIn5 with the field H parallel to the c axis of the tetragonal crystal. The crossing through the…
We consider the one-dimensional massive Thirring model formulated on the lattice with staggered fermions and an auxiliary compact vector (link) field, which is exactly solvable and shows a phase transition with increasing the chemical…
I present the highlights of a recent study of the effective QCD phase diagram on the temperature T and quark chemical potential mu plane, where the strong interactions are modeled using the linear sigma model coupled to quarks. The phase…
The zero-temperature angles of magnetic moments in a helix or sinusoidal fan confined to the xy plane, with respect to an in-plane magnetic field Hx applied perpendicular to the z axis of a helix or fan, are calculated for commensurate…
The experimental studies of the paramagnetic-antiferromagnetic phase transition through M\"{o}ssbauer spectroscopy and measurements of temperature and field dependencies of magnetic susceptibility in the layered Cu$_{0.15}$Fe$_{0.85}$PS$_3$…
We investigate the nature of the phase transition in Josephson junctions arranged on a Kagome lattice. We find that an applied magnetic field corresponding to 1/2 flux quanta per elementary triangle results in a pi phase shift in the…
We present results from lattice simulations of a monolayer graphene model at non-zero temperature. At low temperatures for sufficiently strong coupling the model develops an excitonic condensate of particle-hole pairs corresponding to an…
We report on detailed magnetic measurements on the cubic helimagnet FeGe in external magnetic fields and temperatures near the onset of long-range magnetic order at $T_C= 278.2(3)$ K. Precursor phenomena display a complex succession of…
We determine the finite-temperature phase diagram of the square lattice hard-core boson Hubbard model with nearest neighbor repulsion using quantum Monte Carlo simulations. This model is equivalent to an anisotropic spin-1/2 XXZ model in a…
The critical properties at the ferromagnetic - paramagnetic transition have been analysed from data of static magnetization measurements on single crystals of Pr1-xPbxMnO3, for x = 0.23 and x = 0.30. In Pr1-xPbxMnO3 the ferromagnetic…