Zobrazeno 1 - 10
of 92
pro vyhledávání: '"HASSELMANN, N."'
Autor:
Hasselmann, N., Sinner, A.
Publikováno v:
Phys.Rev.B 90, 094404 (2014)
We investigate two-dimensional frustrated Heisenberg magnets using non-perturbative renormalization group techniques. These magnets allow for point-like topological defects which are believed to unbind and drive either a crossover or a phase transiti
Externí odkaz:
http://arxiv.org/abs/1310.6765
Publikováno v:
J. Phys.: Condens. Matter 24 (2012) 365602
We present a functional renormalization group approach to the zero bias transport properties of a quantum dot with two different orbitals and in presence of Hund's coupling. Tuning the energy separation of the orbital states, the quantum dot can be d
Externí odkaz:
http://arxiv.org/abs/1210.0757
Autor:
Hasselmann, N.
Publikováno v:
Phys. Rev. E 86, 041118 (2012)
We present a truncation scheme of the effective average action approach of the nonperturbative renormalization group which allows for an accurate description of the critical regime as well as of correlation functions at finite momenta. The truncation
Externí odkaz:
http://arxiv.org/abs/1206.6121
Autor:
Hasselmann, N., Braghin, F. L.
Publikováno v:
Phys. Rev. E 83, 031137 (2011)
We investigate the properties of crystalline phantom membranes, at the crumpling transition and in the flat phase, using a nonperturbative renormalization group approach. We avoid a derivative expansion of the effective average action and instead ana
Externí odkaz:
http://arxiv.org/abs/1012.0313
Autor:
Braghin, F. L., Hasselmann, N.
Publikováno v:
Phys. Rev. B 82, 035407 (2010)
We use non-perturbative renormalization group techniques to calculate the momentum dependence of thermal fluctuations of graphene, based on a self-consistent calculation of the momentum dependent elastic constants of a tethered membrane. We find a sh
Externí odkaz:
http://arxiv.org/abs/1003.5116
Increasing experimental and theoretical evidence points towards a dual nature of the 5$f$ electrons in actinide-based strongly correlated metallic compounds, with some 5$f$ electrons being localized and others delocalized. In a recent paper (PRB xxx,
Externí odkaz:
http://arxiv.org/abs/cond-mat/0402124
We investigate a phenomenological model for the spin glass phase of La_{2-x}Sr_xCuO_4, in which it is assumed that holes doped into the CuO_2 planes localize near their Sr dopant, where they cause a dipolar frustration of the antiferromagnetic enviro
Externí odkaz:
http://arxiv.org/abs/cond-mat/0306721
We study the effect of intra-atomic correlations on anisotropies of hopping of 5f electrons. It is shown that they may considerably enhance these anisotropies to the extend that electrons in some of the 5f orbitals remain localized. This provide a mi
Externí odkaz:
http://arxiv.org/abs/cond-mat/0303414
We calculate the influence of transverse fluctuations on the longitudinal dynamics in the striped phase of cuprates by using the bosonization technique. We find that a charge density wave instability can arise if the stripe is quarter filled and the
Externí odkaz:
http://arxiv.org/abs/cond-mat/0112029
We investigate the stripe pinning produced by Nd and Zn co-dopants in cuprates via a renormalization group approach. The two dopants play fundamentally different roles in the pinning process. While Nd induces a correlated pinning potential that traps
Externí odkaz:
http://arxiv.org/abs/cond-mat/0010422