Zobrazeno 1 - 10
of 300
pro vyhledávání: '"Ihle D"'
A microscopic theory of the electronic spectrum and of superconductivity within the t-J model on the honeycomb lattice is developed. We derive the equations for the normal and anomalous Green functions in terms of the Hubbard operators by applying th
Externí odkaz:
http://arxiv.org/abs/1904.13126
We present a spin-rotation-invariant Green-function theory for the dynamic spin susceptibility in the spin-1/2 antiferromagnetic t-J Heisenberg model on the honeycomb lattice. Employing a generalized mean-field approximation for arbitrary temperature
Externí odkaz:
http://arxiv.org/abs/1803.03140
Publikováno v:
Eur. Phys. J. B 90, 48 (2017)
We present a spin-rotation-invariant Green-function theory for the dynamic spin susceptibility in the spin-1/2 antiferromagnetic Heisenberg model on a stacked honeycomb lattice. Employing a generalized mean-field approximation for arbitrary temperatu
Externí odkaz:
http://arxiv.org/abs/1703.08391
Publikováno v:
Phys. Rev. B 95, 134407 (2017)
The thermodynamics of coupled frustrated ferromagnetic chains is studied within a spin-rotation-invariant Green's function approach. We consider an isotropic Heisenberg spin-half system with a ferromagnetic in-chain coupling $J_1<0$ between nearest n
Externí odkaz:
http://arxiv.org/abs/1703.04573
We consider the quasi-two-dimensional pseudo-spin-1/2 Kitaev - Heisenberg model proposed for A2IrO3 (A=Li, Na) compounds. The spin-wave excitation spectrum, the sublattice magnetization, and the transition temperatures are calculated in the random ph
Externí odkaz:
http://arxiv.org/abs/1602.01961
Publikováno v:
Eur. Phys. J. B 88, 148 (2015)
A Green-function theory for the dynamic spin susceptibility in the square-lattice spin-1/2 antiferromagnetic compass-Heisenberg model employing a generalized mean-field approximation is presented. The theory describes magnetic long-range order (LRO)
Externí odkaz:
http://arxiv.org/abs/1506.01834
Publikováno v:
Eur. Phys. J. B 88, 159 (2015)
We use the spin-rotation-invariant Green's function method as well as the high-temperature expansion to discuss the thermodynamic properties of the frustrated spin-$S$ $J_{1}$-$J_{2}$ Heisenberg magnet on the body-centered cubic lattice. We consider
Externí odkaz:
http://arxiv.org/abs/1505.07219
Publikováno v:
JETP Letters 100, 780 (2014)
The spin-wave excitation spectrum, the magnetization, and the N\'{e}el temperature for the quasi-two-dimensional spin-1/2 antiferromagnetic Heisenberg model with compass-model interaction in the plane proposed for iridates are calculated in the rando
Externí odkaz:
http://arxiv.org/abs/1411.3920
Publikováno v:
Journal of Physics: Conference Series 529, 012030 (2014)
The region surrounding the excitonic insulator phase is a three-component plasma composed of electrons, holes, and excitons. Due to the extended nature of the excitons, their presence influences the surrounding electrons and holes. We analyze this co
Externí odkaz:
http://arxiv.org/abs/1409.2230
Publikováno v:
Phys. Rev. B 87, 054412 (2013)
We calculate the temperature dependence of the correlation length xi and the uniform susceptibility chi_0 of the frustrated J1-J2 square-lattice Heisenberg ferromagnet in the collinear stripe phase using Green-function technique. The height chi_{max}
Externí odkaz:
http://arxiv.org/abs/1210.4414