Variational study of the stability of the Nagaoka state against single-spin flips in the two-dimensionalt−t′Hubbard model

2001 ◽  
Vol 63 (23) ◽  
Author(s):  
M. Bajdich ◽  
R. Hlubina
Keyword(s):  
Hubbard Model ◽  
Single Spin ◽  
Variational Study ◽  
The Stability ◽  
Spin Flips

Cross relaxation by single spin flips in silver at nanokelvin temperatures

1990 ◽  
Vol 65 (15) ◽  
pp. 1921-1924 ◽  
Author(s):  
A. S. Oja ◽  
A. J. Annila ◽  
Y. Takano
Keyword(s):  
Cross Relaxation ◽  
Single Spin ◽  
Spin Flips

Determinant Monte Carlo for the Hubbard Model with Arbitrarily Gauged Auxiliary Fields

1992 ◽  
Vol 06 (05n06) ◽  
pp. 547-560 ◽  
Author(s):  
LIANG CHEN ◽  
A.-M.S. TREMBLAY
Keyword(s):  
Monte Carlo ◽  
Phase Space ◽  
Hubbard Model ◽  
Space Exploration ◽  
Field Method ◽  
Intermediate Coupling ◽  
Single Spin ◽  
First Time ◽  
Grand Canonical ◽  
Arbitrary Gauge

Monte Carlo methods for the Hubbard model rely on a Hubbard-Stratonovich (HS) decomposition (auxiliary field method) to perform importance sampling on classical variables. Freedom in the choice of the local HS fields can be formally seen as a gauge choice. While the choice of gauge does not influence observable quantities, it may influence intermediate quantities in the calculation, such as the famous “fermion sign”, and it may also influence the efficiency with which the algorithm explores phase space. The effect of arbitrary gauge choices on both aspects of the algorithm are investigated. It is found that in the single spin-flip determinantal approach, certain gauges lead to a better exploration of phase space. This improvement is demonstrated, in the intermediate coupling regime, by histograms which for the first time show the behavior expected from grand canonical simulations. It is also found that the improved phase space exploration can in practice offset the apparent disadvantage of a smaller fermion sign.

scholarly journals Resolution of Single Spin Flips of a Single Proton

2013 ◽  
Vol 110 (14) ◽  
Author(s):  
A. Mooser ◽  
H. Kracke ◽  
K. Blaum ◽  
S. A. Bräuninger ◽  
K. Franke ◽  
...  
Keyword(s):  
Single Spin ◽  
Single Proton ◽  
Spin Flips

PSEUDOGAP BEHAVIOR IN THE INFINITE DIMENSIONAL ATTRACTIVE HUBBARD MODEL

2011 ◽  
Vol 25 (12n13) ◽  
pp. 973-978 ◽  
Author(s):  
AKIHISA KOGA ◽  
PHILIPP WERNER
Keyword(s):  
Hubbard Model ◽  
Quantum Monte Carlo ◽  
Mean Field Theory ◽  
Mean Field ◽  
Pair Potential ◽  
Infinite Dimensional ◽  
Spatial Dimensions ◽  
Time Quantum ◽  
Attractive Hubbard Model ◽  
The Stability

We study the attractive Hubbard model in infinite spatial dimensions by means of dynamical mean-field theory with continuous-time quantum Monte Carlo simulations. Calculating the pair potential and the spectral function, we discuss the stability of the superfluid state at low temperatures. The pseudogap behavior above the critical temperature is also addressed.

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