https://doi.org/10.1140/epjb/e2018-80712-x
Regular Article
Spin excitations and thermodynamics of the t-J model on the honeycomb lattice
1
Joint Institute for Nuclear Research,
141980
Dubna,
Russia
2
Institut für Theoretische Physik, Universität Leipzig,
04109
Leipzig,
Germany
3
Max-Planck-Institut für Physik komplexer Systeme,
01187
Dresden,
Germany
a e-mail: plakida@theor.jinr.ru
Received:
18
December
2017
Received in final form:
15
May
2018
Published online: 30
August
2018
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 temperatures and hole dopings, the electronic spectrum of excitations, the spin-excitation spectrum and thermodynamic quantities (two-spin correlation functions, staggered magnetization, magnetic susceptibility, correlation length) are calculated by solving a coupled system of self-consistency equations for the correlation functions. The temperature and doping dependence of the magnetic (uniform static) susceptibility is ascribed to antiferromagnetic short-range order. Our results on the doping dependencies of the magnetization and susceptibility are analyzed in comparison with previous results for the t-J model on the square lattice.
Key words: Solid State and Materials
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