相关论文: Quantized \Delta S=2 Excitation Spectra by Confine…
We investigate one-dimensional S=1/2 and S=1 antiferromagnetic quantum spin chains with easy-axis anisotropies in a transverse field. We calculate both the uniform magnetization and the staggered magnetization, using a variant of the…
In the paper we describe the modification of spin-wave theory for one-dimensional isotropic antiferromagnet. This theory enables to obtain the energy of magnetic excitations of short wave length and correlation function in agreement with…
We have studied spin dephasing in a high-mobility two-dimensional electron system (2DES), confined in a GaAs/AlGaAs quantum well grown in the [110] direction, using the resonant spin amplification (RSA) technique. From the characteristic…
The zero-bias anomaly in conductance spectra of single Co atoms on Cu(111) observed at $\approx$ 4 K, which has been interpreted as being due to a Kondo resonance, is strongly modified when the Co atoms are attached to monatomic Cu chains.…
Recently has been investigated that the ground-state wavefunction of the one dimensional quantum spin-1/2 chain models is multifractal in general with non-trivial fractal dimension. We are studying this phenomena for the quantum Ising chain…
We consider random transverse-field Ising spin chains and study the magnetization and the energy-density profiles by numerically exact calculations in rather large finite systems ($L\le 128$). Using different boundary conditions (free,…
The ground state properties and neutron structure factor for the two-dimensional antiferromagnet on the triangular lattice, with uni-directional anisotropy in the nearest-neighbor exchange couplings and a weak Dzyaloshinskii-Moriya (DM)…
The magnetization process of the $S=3/2$ quantum spin chain with the $XXZ$ anisotropy and the single-ion anisotropy $D$ is investigated using the numerical diagonalization of finite-size clusters and the level spectroscopy analysis. We…
We consider the properties of finite isotropic antiferromagnetic Heisenberg chains with S=1/2, 1, 3/2 spins when a weak magnetic field is applied on a few sites, using White's density matrix renormalization group (DMRG) method. For the S=1…
Magnetic field effects on the one-dimensional frustrated ferromagnetic chain are studied by means of effective field theory approaches in combination with numerical calculations utilizing Lanczos diagonalization and the density matrix…
Open segments of S=1 antiferromagnetic spin chains are studied at finite temperatures and fields using continuous time Quantum Monte Carlo techniques. By calculating the resulting magnetization profiles for a large range of chain lengths…
Fractionalization remains one of the most fascinating manifestations of strong interactions in quantum many-body systems. In quantum magnetism, the existence of spinons -- collective magnetic excitations that behave as quasiparticles with…
The anisotropic XXZ spin-1/2 Heisenberg chain is studied using renormalization-group theory. The specific heats and nearest-neighbor spin-spin correlations are calculated thoughout the entire temperature and anisotropy ranges in both…
Using a spin-only model, we compute spin excitation spectra in a bond-centered stripe state with long-range magnetic order. We employ a bond operator formalism, which naturally captures both dimerization and broken spin symmetry in a…
The spin dynamics and magnetic excitations of the slightly distorted triangular s = 3/2 system alpha-CaCr2O4 are investigated by means of Raman spectroscopy and electron spin resonance (ESR) to elucidate its peculiar magnetic properties.…
Confinement is a process by which particles with fractional quantum numbers bind together to form quasiparticles with integer quantum numbers. The constituent particles are confined by an attractive interaction whose strength increases with…
We study the first derivative of the staggered magnetization squared $dm^\dag(\theta)^2/d\theta$ and the second derivative $d^2e_0(\theta)/d\theta^2$ of the ground state energy per site. The parameter $\theta$ controls the anisotropy…
Confinement of fractionalized excitations can strongly restructure many-body spectra. We investigate this phenomenon in the gapped spin-$\frac{1}{2}$ XXZ chain subject to a staggered field, where spinons bind into domain-wall ``mesons''…
The static structure factor S(q) of frustrated spin-1/2 chains with isotropic exchange and a singlet ground state (GS) diverges at wave vector q_m when the GS has quasi-long-range order (QLRO) with periodicity 2\pi/q_m but S(q_m) is finite…
Spin dynamics of two-dimensional electron gas confined in an asymmetrical quantum well is studied theoretically in the regime where the scattering frequency is comparable with the spin precession frequency due to the conduction band spin…