相关论文: Percolative conductivity and critical exponents in…
We present the metal - insulator transition study of a quantum site percolation model on simple cubic lattice. Transfer matrix method is used to calculate transport properties - Landauer conductance - for the binary distribution of…
In conventional metals, electronic transport in a magnetic field is characterized by the motion of electrons along orbits on the Fermi surface, which usually causes an increase in the resistivity through averaging over velocities. Here we…
We show detailed derivation of the electric conductivity of quark matter at finite temperature and density under a magnetic field. We especially focus on the longitudinal electric conductivity along the magnetic direction and establish the…
Metal-insulator transitions driven by magnetic fields have been extensively studied in 2D, but a 3D theory is still lacking. Motivated by recent experiments, we develop a scaling theory for the metal-insulator transitions in the…
Upon substituting Ca for Eu in the local-moment ferromagnet EuB$_6$, the Curie temperature $T_C$ decreases substantially with increasing dilution of the magnetic sublattice and is completely suppressed for $x$ $\leq$ 0.3. The Ca…
A double percolation transition is identified in a binary network composed of nanoparticles of magnesium diborade superconductor and chromium oxide half-metallic ferromagnet. Anomalously high-resistance or insulating state, as compared to…
The relevance of pair-breaking by exchange and dipolar fields, and by injected spins in a low carrier density cuprate Y$_{1-x}$Pr$_x$Ba$_2$Cu$_3$O$_7$ sandwiched between two ferromagnetic La$_{2 / 3}$Sr$_{1 / 3}$MnO$_{3}$ layers is…
We have studied the terahertz response of a bulk single crystal of La$_{0.875}$Sr$_{0.125}$MnO$_3$ at around its Curie temperature, observing large changes in the real and imaginary parts of the optical conductivity as a function of…
Transport properties of manganese oxides suggest that their colossal magnetoresistance (CMR) is due to percolation between ferromagnetic metallic (FM) clusters in an antiferromagnetic insulating (AFI) matrix. We have studied small-angle…
The electronic properties of many transition metal oxide systems require new ideas concerning the behaviour of electrons in solids for their explanation. A recent example, subsequent to that of cuprate superconductors, is of rare earth…
We develop a hydrodynamic description of electron magnetotransport in conductors without Galilean invariance in the presence of a weak long-range disorder potential. We show that magnetoresistance becomes strong (of order 100 %) at…
Within massive gravity, we construct a gravity dual for insulator/metal phase transition and colossal magnetoresistance (CMR) effect found in some manganese oxides materials. In heavy graviton limit, a remarkable magnetic-field-sensitive DC…
We study the dynamic vortex Mott transition in two-dimensional superconducting arrays in a magnetic field with $f$ flux quantum per plaquette. The transition is induced by external driving current and thermal fluctuations near rational…
Our investigation of the magnetotransport in two charge ordered manganites with similar magnetic ground states reveals that the origin of magnetoresistance can not be concluded from the isofield resistivity, $\rho $(T, constant H),…
We report magnetic properties of the layered itinerant system, Sr$_{1-x}$Ca$_x$Co$_2$P$_2$ in the magnetic field up to 70 T. As for the exchange-enhanced Pauli paramagnetic metal SrCo$_2$P$_2$, the magnetization curve shows two…
Substitutions at the Mn-site of the charge-ordered Pr0.5Ca0.5MnO3 manganite is an effective way to induce abrupt jumps on the magnetic field driven magnetization curve. In order to get new insights into the origin of this remarkable…
We theoretically explore the mechanism of the colossal magnetoresistance in manganese oxides by explicitly taking into account the phase competition between the double-exchange ferromagnetism and the charge-ordered insulator. We find that…
Using 20 months of CPU time on our special purpose computer ``Percola'' we determined the exponent for the normal conductivity at the threshold of three-dimensional site and bond percolation. The extrapolation analysis taking into account…
We develop a variational mean-field theory of the ferromagnetic transition in compounds like Lanthanum-Manganite within the framework of the Double-Exchange Model supplemented by modest disorder. We obtain analytical expressions for the…
We have investigated the effect of oxygen isotope substitution on the metal-insulator transition temperature and the resistivity of the narrow band manganite (La0.25Pr0.75)0.7Ca0.3MnO3 in a constant magnetic field. A set of 16 samples…