Zobrazeno 1 - 10
of 203
pro vyhledávání: '"Blümer N"'
Autor:
Rost, D., Blümer, N.
We present an algorithm for the computation of unbiased Green functions and self-energies for quantum lattice models, free from systematic errors and valid in the thermodynamic limit. The method combines direct lattice simulations using the Blankenbe
Externí odkaz:
http://arxiv.org/abs/1504.05090
Autor:
Schäfer, T., Geles, F., Rost, D., Rohringer, G., Arrigoni, E., Held, K., Blümer, N., Aichhorn, M., Toschi, A.
Publikováno v:
Phys. Rev. B 91, 125109 (2015)
We have studied the impact of non-local electronic correlations at all length scales on the Mott-Hubbard metal-insulator transition in the unfrustrated two-dimensional Hubbard model. Combining dynamical vertex approximation, lattice quantum Monte-Car
Externí odkaz:
http://arxiv.org/abs/1405.7250
Autor:
Gorelik, E. V., Blümer, N.
Localized defects, unavoidable in real solids, may be simulated in (generically defect-free) cold-atom systems, e.g., via modifications of the optical lattice. We study the Hubbard model on a square lattice with single impurities, pairs of nearby imp
Externí odkaz:
http://arxiv.org/abs/1405.0404
Publikováno v:
Phys. Rev. E 87, 053305 (2013)
We present an algorithm for solving the self-consistency equations of the dynamical mean-field theory (DMFT) with high precision and efficiency at low temperatures. In each DMFT iteration, the impurity problem is mapped to an auxiliary Hamiltonian, f
Externí odkaz:
http://arxiv.org/abs/1303.2004
Publikováno v:
Phys. Rev. B 87, 205135 (2013)
We investigate the effects of crystal field splitting in a doped two-band Hubbard model with different bandwidths within dynamical mean-field theory (DMFT), using a quantum Monte Carlo impurity solver. In addition to an orbital-selective Mott phase (
Externí odkaz:
http://arxiv.org/abs/1301.7252
Autor:
Blümer, N., Gorelik, E.
Publikováno v:
Phys. Rev. B 87, 085115 (2013)
The Hubbard model with large orbital degeneracy has recently gained relevance in the context of ultracold earth alkali like atoms. We compute its static properties in the SU(2M) symmetric limit for up to M=8 bands at half filling within dynamical mea
Externí odkaz:
http://arxiv.org/abs/1212.4485
Publikováno v:
Phys. Rev. B 86, 155109 (2012)
We compute unbiased spectral functions of the two-dimensional Hubbard model by extrapolating Green functions, obtained from determinantal quantum Monte Carlo simulations, to the thermodynamic and continuous time limits. Our results clearly resolve th
Externí odkaz:
http://arxiv.org/abs/1205.6788
Universal probes for antiferromagnetic correlations and entropy in cold fermions on optical lattices
Publikováno v:
Phys. Rev. A 85, 061602(R) (2012)
We determine antiferromagnetic (AF) signatures in the half-filled Hubbard model at strong coupling on a cubic lattice and in lower dimensions. Upon cooling, the transition from the charge-excitation regime to the AF Heisenberg regime is signaled by a
Externí odkaz:
http://arxiv.org/abs/1201.5576
We verify signatures of antiferromagnetic (AF) correlations in the double occupancy D [Gorelik et al., PRL 105, 065301 (2010)] and study their dimensional dependence using direct quantum Monte Carlo in dimensions d=2,3 and Bethe Ansatz in d=1. We fin
Externí odkaz:
http://arxiv.org/abs/1105.3356
Autor:
Blümer, N., Gorelik, E. V.
Publikováno v:
Computer Physics Communications 118, 115 (2011)
We present a massively parallel quantum Monte Carlo based implementation of real-space dynamical mean-field theory for general inhomogeneous correlated fermionic lattice systems. As a first application, we study magnetic order in a binary mixture of
Externí odkaz:
http://arxiv.org/abs/1006.2716