Physics – Condensed Matter – Quantum Gases
Scientific paper
2012-03-06
Physics
Condensed Matter
Quantum Gases
16 pages, 12 figures
Scientific paper
We use strong-coupling perturbation theory, the variational cluster approach (VCA), and the dynamical density-matrix renormalization group (DDMRG) method to investigate static and dynamical properties of the one-dimensional Bose--Hubbard model in both the Mott-insulating and superfluid phases. From the von-Neumann entanglement entropy we determine the central charge and the transition points for the first two Mott lobes. Our DMRG results for the ground-state energy, momentum distribution function, boson correlation function decay, Mott gap, and single particle-spectral function are reproduced very well by the strong-coupling expansion to fifth order (VCA with 12 sites) as long as the ratio between the hopping amplitude and on-site repulsion, t/U, is smaller than 0.15 (0.25). This comparison provides an authoritative estimate for the range of applicability of these methods. In strong-coupling theory for the Mott phase, the dynamical structure factor is obtained from the solution of an effective single-particle problem with an attractive potential. The resulting resonances show up as double-peak structure close to the Brillouin zone boundary. These high-energy features also appear in the superfluid phase which is characterized by a pronounced phonon mode at small momenta and energies, as predicted by Bogoliubov and field theory. In one dimension, there are no traces of an amplitude mode in the dynamical single-particle and two-particle correlation functions.
Arrigoni Enrico
der Linden Wolfgang von
Ejima Satoshi
Fehske Holger
Gebhard Florian
No associations
LandOfFree
Characterization of Mott-insulating and superfluid phases in the one-dimensional Bose--Hubbard model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Characterization of Mott-insulating and superfluid phases in the one-dimensional Bose--Hubbard model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Characterization of Mott-insulating and superfluid phases in the one-dimensional Bose--Hubbard model will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-536848