Related papers: Quantum Ferromagnetic Transition in Clean Dirac Me…
Quantum criticality is the intriguing possibility offered by the laws of quantum mechanics when the wave function of a many-particle physical system is forced to evolve continuously between two distinct, competing ground states. This…
Spin correlations in metallic and insulating phases of $V_2O_3$ and its derivatives are investigated using magnetic neutron scattering. Metallic samples have incommensurate spin correlations varying little with hole doping. Paramagnetic…
The properties and mechanism of the magnetic phase transition of the perovskite-type Ti oxides, which is driven by the Ti-O-Ti bond angle distortion, are studied theoretically by using the effective spin and pseudospin Hamiltonian with…
The electrons on the surface of a disordered multi-layer integer quantum Hall system constitute an unusual chiral metal with ballistic motion transverse to the field, and diffusive motion parallel to it. We present a non-perturbative…
We study the (2+1) dimensional Dirac oscillator in a homogeneous magnetic field in the non-commutative plane. It is shown that the effect of non-commutativity is twofold: $i$) momentum non commuting coordinates simply shift the critical…
From general arguments, that are valid for spin models with sufficiently short-range interactions, we derive strong constraints on the excitation spectrum across a continuous phase transition at zero temperature between a magnetic and a…
The magnetic susceptibility of an ensemble of clean metallic nanoparticles is shown to change from paramagnetic to diamagnetic one with the onset of spin-orbit interaction. The effect is quantified on the basis of symmetry analysis with the…
The dynamics at the critical-point of a general first-order quantum phase transition in a finite system is examined, from an algebraic perspective. Suitable Hamiltonians are constructed whose spectra exhibit coexistence of states…
Strange-metal phenomena often develop at the border of antiferromagnetic order in strongly correlated metals. It has been well established that they can originate from the fluctuations anchored by the point of continuous quantum phase…
We study superconductivity in a three-dimensional zero-density Dirac semimetal in proximity to a ferroelectric quantum critical point. We find that the interplay of criticality, inversion-symmetry breaking, and Dirac dispersion gives rise…
It was discovered in La1-xSrxMnO3(x~1/8) that a field induced phase transition occurs from a ferromagnetic metal(FM) phase to a ferromagnetic insulator (FI) phase. The magnetization shows a sharp jump at the transition field accompanying…
Magnetic state is a partial ordered state if only part of the electrons in the system give contribution to the magnetic order. We study Heisenberg model of two sublattice spin system, on the body-centered cubic lattice, with…
We investigate the interplay of quantum fluctuations and magnetic anisotropies in metallic ferromagnets. Our central result is that fluctuations close to a quantum critical point can drive the moments to point along a magnetic hard axis. As…
A variety of compounds, for example doped paraelectrics and polar metals, exhibit both ferroelectricity and correlated electronic phenomena such as low-density superconductivity and anomalous transport. Characterizing such properties is…
We investigate the effect of strong electronic correlation on the massless Dirac fermion system, $\alpha$-(BEDT-TTF)$_2$I$_3$, under pressure. In this organic salt, one can control the electronic correlation by changing pressure and access…
The quantum ferromagnetic transition of itinerant electrons is considered. We give a pedagogical review of recent results which show that zero-temperature soft modes that are commonly neglected, invalidate the standard…
A mechanism for charge-ordered ferromagnetic phase in manganites is proposed. The mechanism is based on the double exchange in the presence of diagonal disorder. It is modeled by a combination of the Ising double-exchange and the…
We discuss the properties of possible ferromagnetic orders on the Lieb lattice. We show that the presence of a quadratic-flat band crossing point (QFBCP) at half filling will dramatically affect the magnetic ordering. In the presence of a…
An effective field theory is derived that describes the quantum critical behavior of itinerant ferromagnets as the transition is approached from the ferromagnetic phase. This complements a recent study of the critical behavior on the…
We show using quantum free energy calculation that the quantum phase transition between U(1) quantum spin liquid (QSL) and antiferromagnet (AFM) phases in pyrochlore quantum antiferromagnet (QAFM) is a first order rather than second order.…