Zobrazeno 1 - 10
of 609
pro vyhledávání: '"Oitmaa, J."'
Publikováno v:
Phys. Rev. B 98, 214404 (2018)
We present results on entropy and heat-capacity of the spin-S honeycomb-lattice Kitaev models using high-temperature series expansions and thermal pure quantum (TPQ) state methods. We study models with anisotropic couplings $J_z=1\ge J_x=J_y$ for spi
Externí odkaz:
http://arxiv.org/abs/1809.10112
Autor:
Rawl, R., Ge, L., Agrawal, H., Kamiya, Y., Cruz, C. R. Dela, Butch, N. P., Sun, X. F., Lee, M., Choi, E. S., Oitmaa, J., Batista, C. D., Mourigal, M., Zhou, H. D., Ma, J.
Publikováno v:
Phys. Rev. B 95, 060412 (2017)
The perovskite Ba8CoNb6O24 comprises equilateral effective spin-1/2 Co2+ triangular layers separated by six non-magnetic layers. Susceptibility, specific heat and neutron scattering measurements combined with high-temperature series expansions and sp
Externí odkaz:
http://arxiv.org/abs/1612.04117
Autor:
Jaubert, L. D. C., Benton, Owen, Rau, Jeffrey G., Oitmaa, J., Singh, R. R. P., Shannon, Nic, Gingras, Michel J. P.
Publikováno v:
Phys. Rev. Lett. 115, 267208 (2015)
If magnetic frustration is most commonly known for undermining long-range order, as famously illustrated by spin liquids, the ability of matter to develop new collective mechanisms in order to fight frustration is no less fascinating, providing an av
Externí odkaz:
http://arxiv.org/abs/1505.05499
Publikováno v:
Published in Phys. Rev. B, 134423 (2015)
We investigate the excitation spectrum of the triangular-lattice antiferromagnetic $XXZ$ model using series expansions and mean field Schwinger bosons approaches. The single-magnon spectrum computed with series expansions exhibits rotonic minima at t
Externí odkaz:
http://arxiv.org/abs/1411.5298
Publikováno v:
Phys. Rev. B 88, 220404(R) (2013)
Several rare earth magnetic pyrochlore materials are well modeled by a spin-1/2 quantum Hamiltonian with anisotropic exchange parameters Js. For the Er2Ti2O7 material, the Js were recently determined from high-field inelastic neutron scattering measu
Externí odkaz:
http://arxiv.org/abs/1305.2935
We present a Quantum Monte Carlo study of the Ising model in a transverse field on a square lattice with nearest-neighbor antiferromagnetic exchange interaction J and one diagonal second-neighbor interaction $J'$, interpolating between square-lattice
Externí odkaz:
http://arxiv.org/abs/1303.0883
Autor:
Singh, Rajiv R. P., Oitmaa, J.
Publikováno v:
Phys. Rev. B 85, 144414 (2012)
We study corrections to single tetrahedron based approximations for the entropy, specific heat and uniform susceptibility of the pyrochlore lattice Ising antiferromagnet, by a Numerical Linked Cluster (NLC) expansion. In a tetrahedron based NLC, the
Externí odkaz:
http://arxiv.org/abs/1112.4439
Autor:
Singh, R. R. P., Oitmaa, J.
Publikováno v:
Phys. Rev. B 85, 104406 (2012)
We develop high temperature series expansions for $\ln{Z}$ and the uniform structure factor of the spin-half Heisenberg model on the hyperkagome lattice to order $\beta^{16}$. These expansions are used to calculate the uniform susceptibility ($\chi$)
Externí odkaz:
http://arxiv.org/abs/1112.4197
Autor:
Oitmaa, J., Singh, R. R. P.
Publikováno v:
Phys. Rev. B 85, 014428 (2012)
Motivated by the observation of a disordered spin ground state in the $S=3/2$ material Bi$_3$Mn$_4$O$_{12}$NO$_3$, we study the ground state properties and excitation spectra of the $S=3/2$ (and for comparison $S=1/2$) bilayer Heisenberg model on the
Externí odkaz:
http://arxiv.org/abs/1111.6529
We consider a 3-dimensional quantum antiferromagnet which can be driven through a quantum critical point (QCP) by varying a tuning parameter g. Starting from the magnetically ordered phase, the N{\'e}el temperature will decrease to zero as the QCP is
Externí odkaz:
http://arxiv.org/abs/1110.6478