Related papers: Electronic Ferroelectricity in a Dimer Mott Insula…
We have investigated dielectric properties in Mott insulators GdMnO$_{3}$ and TbMnO$_{3}$ under magnetic fields and external quasihydrostatic pressures. In the case of GdMnO$_{3}$, thermal hysteresis for dielectric constant $\epsilon$ and…
The organic charge-transfer salt $\kappa$-(BEDT-TTF)$_{2}$Hg(SCN)$_{2}$Br is a quasi two-dimensional metal with a half-filled conduction band at ambient conditions. When cooled below $T=80$ K it undergoes a pronounced transition to an…
Some well-established examples of itinerant-electron ferromagnetism in one dimension occur in a Mott-insulating phase. We examine the consequences of doping a ferromagnetic insulator and cou- pling magnons to gapless charge fluctuations.…
We have studied the interlayer resistivity of the prototypical quasi-two-dimensional organic superconductor $\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$ as a function of temperature, current and magnetic field, within the superconducting state. We…
Ab initio calculations of the electric polarization of correlation-driven insulating materials, namely Mott insulators, have not been possible so far. Using a combination of density functional theory and dynamical-mean-field theory we study…
An influence of the localization of itinerant electrons induced by correlated hopping on the electronic charge and heat transport is discussed for the lightly doped Mott insulator phase of the Falicov-Kimball model. The case of strongly…
Field-induced antiferromagnetic (AF) fluctuations and magnetization are observed above the (zero-field) ordering temperature, T_N = 23 K by electron spin resonance in kappa-(BEDT-TTF)_2Cu[N(CN)_2]Cl, a quasi two-dimensional antiferromagnet…
Strong commensurate antiferromagnetism proximate to superconductivity is found in some members of the kappa-(ET) family, while a spin gap (SG) is found in the theta-(ET). Both kappa- and theta-(ET) materials have frustrated triangular…
Resistance noise spectroscopy is applied to bulk single crystals of the quasi-two-dimensional organic Mott insulator $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Cl both under moderate pressure and at ambient-pressure conditions. When pressurized,…
The spin excitations from the nonmagnetic charge-ordered insulating state of $\alpha$-(BEDT-TTF)$_2$I$_3$ at ambient pressure have been investigated by probing the static and low-frequency dynamic spin susceptibilities via site-selective…
We prospect magneto-dielectricity in $La_{0.53}Ca_{0.47}MnO_{3}$ across its paramagnetic (PMI) to ferromagnetic (FMM) isostructural transition at $T_{C} \sim 253K$, by magnetic ($(M)$), caloric ($(W)$), dielectric ($(\epsilon')$),…
We investigate the magnetic and the transport properties of diluted magnetic semiconductors using a spin-fermion Monte-Carlo method on a 3D lattice in the intermediate coupling regime. The ferromagnetic transition temperature $T_c$ shows an…
Correlated electrons in a binary alloy $A_{x}B_{1-x}$ are investigated within the Hubbard model and dynamical mean--field theory (DMFT). The random energies $\epsilon_{i}$ have a bimodal probability distribution and an energy separation…
The development of long-range ferromagnetic (FM) order in dilute magnetic topological insulators can induce dissipationless electronic surface transport via the quantum anomalous Hall effect. We measure the magnetic excitations in a…
We report a novel insulator-insulator transition arising from the internal charge degrees of freedom in the two-dimensional quarter-filled organic salt beta-(meso-DMBEDT-TTF)2PF6. The optical conductivity spectra above Tc = 70 K display a…
Sustaining exotic quantum mechanical phases at high temperatures is a long-standing goal of condensed matter physics. Among them, half-metals are spin-polarized conductors that are essential for realizing room-temperature spin current…
We present comparative theoretical investigation of thermoelectric power and Hall effect in the Hubbard model for correlated metal and Mott insulator (considered as prototype cuprate superconductor) for different concentrations of current…
Strong electronic interactions can drive a system into a state with a symmetry breaking. Lattice frustration or competing interactions tend to prevent a symmetry breaking, leading to quantum disordered phases. In spin systems frustration…
We derive an effective field theory model for magnetic topological insulators and predict that a magnetic electronic gap persists on the surface for temperatures above the ordering temperature of the bulk. Our analysis also applies to…
We develop a theory of the magneto-optical and magneto-electric properties of a topological insulator thin film in the presence of a quantizing external magnetic field. We find that low-frequency magneto-optical properties depend only on…