Auxiliary-space variational approach for theU=∞ Hubbard model: The stability of a ferromagnetic state

1992 ◽  
Vol 45 (22) ◽  
pp. 12996-13001 ◽  
Author(s):  
V. Ya. Krivnov ◽  
A. A. Ovchinnikov
Keyword(s):  
Hubbard Model ◽  
Variational Approach ◽  
Ferromagnetic State ◽  
Auxiliary Space ◽  
The Stability

ON THE INSTABILITY OF THE FERROMAGNETIC STATE IN THE U=∞ LIMIT OF THE HUBBARD MODEL

1989 ◽  
Vol 03 (12) ◽  
pp. 1755-1764 ◽  
Author(s):  
B. Douçot ◽  
R. Rammal
Keyword(s):  
Coherent State ◽  
Hubbard Model ◽  
Ground State ◽  
Variational Approach ◽  
Ferromagnetic State ◽  
Finite Density

The U=∞ limit of the Hubbard model is studied using a variational approach in which the spins are in a static coherent state. We find that the Nagaoka Ferromagnetic state is no longer the ground state as soon as two holes are present, and this for various geometries. We suggest that this instability also remains for a finite density of holes.

scholarly journals Scaling properties of the ferromagnetic state in the Hubbard model

1994 ◽  
Vol 50 (17) ◽  
pp. 12991-12994 ◽  
Author(s):  
K. Kusakabe ◽  
H. Aoki
Keyword(s):  
Hubbard Model ◽  
Ferromagnetic State ◽  
Scaling Properties

Hubbard model in the ferromagnetic state. Dimer and trimer approach

2005 ◽  
Vol 242 (2) ◽  
pp. 337-341 ◽  
Author(s):  
M. Matlak ◽  
T. Słomska ◽  
B. Grabiec
Keyword(s):  
Hubbard Model ◽  
Ferromagnetic State

Variational Approach for the Bose–Hubbard Model

2008 ◽  
Vol 25 (5) ◽  
pp. 1792-1794
Author(s):  
Yu De-Shui ◽  
Chen Jing-Biao
Keyword(s):  
Hubbard Model ◽  
Variational Approach

A variational approach to the stability of an embedded NLS soliton at the edge of the continuum

2005 ◽  
Vol 206 (3-4) ◽  
pp. 166-179 ◽  
Author(s):  
A.A. Minzoni ◽  
Noel F. Smyth ◽  
Annette L. Worthy
Keyword(s):  
Variational Approach ◽  
The Stability ◽  
The Continuum

scholarly journals Stability of disk-like galaxies – Part I: Stability via reduction

Analysis ◽  
2006 ◽  
Vol 26 (4) ◽  
Author(s):  
Roman Fiřt ◽  
Gerhard Rein
Keyword(s):  
Stability Problem ◽  
Variational Approach ◽  
Steady States ◽  
Poisson System ◽  
Reduction Procedure ◽  
Analogous Question ◽  
Existence And Stability ◽  
The Stability

We prove the existence and stability of flat steady states of the Vlasov–Poisson system, which in astrophysics are used as models of disk-like galaxies. We follow the variational approach developed by GUO and REIN [5, 6, 7] for this type of problems and extend previous results of REIN [11]. In particular, we employ a reduction procedure which relates the stability problem for the Vlasov–Poisson system to the analogous question for the Euler–Poisson system.

scholarly journals Metallic and insulating stripes and their relation with superconductivity in the doped Hubbard model

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Luca Fausto Tocchio ◽  
Arianna Montorsi ◽  
Federico Becca
Keyword(s):  
Hubbard Model ◽  
Quantum Monte Carlo ◽  
Variational Approach ◽  
Wave Functions ◽  
Density Matrix Renormalization Group ◽  
Strongly Correlated ◽  
Density Matrix Renormalization ◽  
Spin Modulation ◽  
Stripe Order ◽  
Superconducting Correlations

The dualism between superconductivity and charge/spin modulations (the so-called stripes) dominates the phase diagram of many strongly-correlated systems. A prominent example is given by the Hubbard model, where these phases compete and possibly coexist in a wide regime of electron dopings for both weak and strong couplings. Here, we investigate this antagonism within a variational approach that is based upon Jastrow-Slater wave functions, including backflow correlations, which can be treated within a quantum Monte Carlo procedure. We focus on clusters having a ladder geometry with MM legs (with MM ranging from 22 to 1010) and a relatively large number of rungs, thus allowing us a detailed analysis in terms of the stripe length. We find that stripe order with periodicity \lambda=8λ=8 in the charge and 2\lambda=162λ=16 in the spin can be stabilized at doping \delta=1/8δ=1/8. Here, there are no sizable superconducting correlations and the ground state has an insulating character. A similar situation, with \lambda=6λ=6, appears at \delta=1/6δ=1/6. Instead, for smaller values of dopings, stripes can be still stabilized, but they are weakly metallic at \delta=1/12δ=1/12 and metallic with strong superconducting correlations at \delta=1/10δ=1/10, as well as for intermediate (incommensurate) dopings. Remarkably, we observe that spin modulation plays a major role in stripe formation, since it is crucial to obtain a stable striped state upon optimization. The relevance of our calculations for previous density-matrix renormalization group results and for the two-dimensional case is also discussed.

Sign in / Sign up

Export Citation Format

Share Document