Zobrazeno 1 - 10
of 580
pro vyhledávání: '"Bulla, R"'
Publikováno v:
Phys. Rev. B 78, 035434 (2008)
We investigate non-equilibrium two-electron transfer in a model redox system represented by a two-site extended Hubbard model and embedded in a dissipative environment. The influence of the electron-electron interactions and the coupling to a dissipa
Externí odkaz:
http://arxiv.org/abs/0803.4066
Autor:
Sindel, M., Borda, L., Martinek, J., Bulla, R., Koenig, J., Schoen, G., Maekawa, S., von Delft, J.
Publikováno v:
Phys. Rev. B 76, 045321 (2007)
We systematically study the influence of ferromagnetic leads on the Kondo resonance in a quantum dot tuned to the local moment regime. We employ Wilson's numerical renormalization group method, extended to handle leads with a spin asymmetric density
Externí odkaz:
http://arxiv.org/abs/0706.3997
Measurements of electron transfer rates as well as of charge transport characteristics in DNA produced a number of seemingly contradictory results, ranging from insulating behaviour to the suggestion that DNA is an efficient medium for charge transpo
Externí odkaz:
http://arxiv.org/abs/cond-mat/0604440
Autor:
Vollhardt, D., Held, K., Keller, G., Bulla, R., Pruschke, Th., Nekrasov, I. A., Anisimov, V. I.
Publikováno v:
J. Phys. Soc. Jpn. 74, 136 (2005)
Dynamical mean-field theory (DMFT) is a non-perturbative technique for the investigation of correlated electron systems. Its combination with the local density approximation (LDA) has recently led to a material-specific computational scheme for the a
Externí odkaz:
http://arxiv.org/abs/cond-mat/0408266
Autor:
Lee, H. -J., Bulla, R.
The numerical renormalization group method is used to investigate zero temperature phase transitions in quantum impurity systems, in particular in the soft-gap Anderson model, where an impurity couples to a non-trivial fermionic bath. In this case, z
Externí odkaz:
http://arxiv.org/abs/cond-mat/0406557
Autor:
Martinek, J., Sindel, M., Borda, L., Barnas, J., Bulla, R., König, J., Schön, G., Maekawa, S., von Delft, J.
Publikováno v:
Phys. Rev. B 72, 121302(R) (2005)
The effect of a gate voltage ($V_g$) on the spin-splitting of an electronic level in a quantum dot (QD) attached to ferromagnetic leads is studied in the Kondo regime using a generalized numerical renormalization group technique. We find that the $V_
Externí odkaz:
http://arxiv.org/abs/cond-mat/0406323
Publikováno v:
Physical Review Letters 93, 016406 (2004)
The Mott-Hubbard metal-insulator transition in the paramagnetic phase of the one-band Hubbard model has long been used to describe similar features in real materials like V$_2$O$_3$. Here we show that this transition is hidden inside a rather robust
Externí odkaz:
http://arxiv.org/abs/cond-mat/0308202
Publikováno v:
Phys. Rev. B 67, 155102--1-8 (2003)
Inelastic light scattering from electrons is a symmetry-selective probe of the charge dynamics within correlated materials. Many measurements have been made on correlated insulators, and recent exact solutions in large dimensions explain a number of
Externí odkaz:
http://arxiv.org/abs/cond-mat/0211387
Publikováno v:
in Concepts in Electron Correlations, A.C. Hewson and V. Zlatic (eds.), Kluwer Academic Publishers, Dordrecht (2003), 209
Zero temperature phase transitions not only occur in the bulk of quantum systems, but also at boundaries or impurities. We review recent work on quantum phase transitions in impurity models that are generalizations of the standard Kondo model describ
Externí odkaz:
http://arxiv.org/abs/cond-mat/0210015
Mott metal-insulator transitions in an M-fold orbitally degenerate Hubbard model are studied by means of a generalization of the linearized dynamical mean-field theory. The method allows for an efficient and reliable determination of the critical int
Externí odkaz:
http://arxiv.org/abs/cond-mat/0206508