Zobrazeno 1 - 10
of 34
pro vyhledávání: '"Garcia Palacios, J. L."'
Publikováno v:
Phys. Rev. B 85, 195452 (2012)
We develop a general theory for thermal transport in anharmonic systems under the weak system-bath coupling approximation similar to the quantum master equation formalism. A current operator is derived, which is valid not only in the steady state, bu
Externí odkaz:
http://arxiv.org/abs/1202.6262
The equilibrium susceptibility of uniaxial paramagnets is studied in a unified framework which permits to connect traditional results of the theory of quantum paramagnets, $\Sm=1/2, 1, 3/2$, ..., with molecular magnetic clusters, $\Sm\sim5, 10, 20$,
Externí odkaz:
http://arxiv.org/abs/0907.3181
Autor:
Garcia-Palacios, J. L.
Publikováno v:
Advances in Chemical Physics, vol. 112 (2000) 1-210
Sec I - Introduction Sec II - Equilibrium properties: generalities and methodology Sec III - Equilibrium properties: some important quantities Sec IV - Dynamical properties: heuristic approach Sec V - Dynamical properties: stochastic approach Sec VI
Externí odkaz:
http://arxiv.org/abs/0906.5246
Autor:
Garcia-Palacios, J. L.
These notes are an introduction to the theory of stochastic processes based on several sources. The presentation mainly follows the books of van Kampen and Wio, except for the introduction, which is taken from the book of Gardiner and the parts devot
Externí odkaz:
http://arxiv.org/abs/cond-mat/0701242
Quantum nanomagnets can show a field dependence of the relaxation time very different from their classical counterparts, due to resonant tunneling via excited states (near the anisotropy barrier top). The relaxation time then shows minima at the reso
Externí odkaz:
http://arxiv.org/abs/cond-mat/0606091
Autor:
Garcia-Palacios, J. L., Zueco, D.
We implement continued-fraction techniques to solve exactly quantum master equations for a spin with arbitrary S coupled to a (bosonic) thermal bath. The full spin density matrix is obtained, so that along with relaxation and thermoactivation, cohere
Externí odkaz:
http://arxiv.org/abs/cond-mat/0603730
Autor:
Garcia-Palacios, J. L.
The continued-fraction method was developed systematically by Risken and co-workers to solve problems of arbitrary fluctuations in nonlinear systems. However, this efficient technique is limited to problems with a few variables, which in practice mea
Externí odkaz:
http://arxiv.org/abs/cond-mat/0602072
Autor:
Zueco, D., Garcia-Palacios, J. l.
The relaxation mechanisms of a quantum nanomagnet are discussed in the frame of linear response theory. We use a spin Hamiltonian with a uniaxial potential barrier plus a Zeeman term. The spin, having arbitrary $S$, is coupled to a bosonic environmen
Externí odkaz:
http://arxiv.org/abs/cond-mat/0509627
Publikováno v:
Phys. Rev. B 72, 224433 (2005)
We present an experimental study of the {\em nonlinear} susceptibility of Mn$_{12}$ single-molecule magnets. We investigate both their thermal-equilibrium and dynamical nonlinear responses. The equilibrium results show the sensitivity of the nonlinea
Externí odkaz:
http://arxiv.org/abs/cond-mat/0508284
Autor:
Garcia-Palacios, J. L., Dattagupta, S.
Publikováno v:
Phys. Rev. Lett. 95, 190401 (2005)
We address the problem of spin dynamics in the presence of a thermal bath, by solving exactly the appropriate quantum master equations with continued-fraction methods. The crossover region between the quantum and classical domains is studied by incre
Externí odkaz:
http://arxiv.org/abs/quant-ph/0505002