11,138 research outputs found
Universal Tomonaga-Luttinger liquid phases in one-dimensional strongly attractive SU(N) fermionic cold atoms
A simple set of algebraic equations is derived for the exact low-temperature
thermodynamics of one-dimensional multi-component strongly attractive fermionic
atoms with enlarged SU(N) spin symmetry and Zeeman splitting. Universal
multi-component Tomonaga-Luttinger liquid (TLL) phases are thus determined. For
linear Zeeman splitting, the physics of the gapless phase at low temperatures
belongs to the universality class of a two-component asymmetric TLL
corresponding to spin-neutral N-atom composites and spin-(N-1)/2 single atoms.
The equation of states is also obtained to open up the study of multi-component
TLL phases in 1D systems of N-component Fermi gases with population imbalance.Comment: 12 pages, 3 figure
Wilson ratio of Fermi gases in one dimension
We calculate the Wilson ratio of the one-dimensional Fermi gas with spin
imbalance. The Wilson ratio of attractively interacting fermions is solely
determined by the density stiffness and sound velocity of pairs and of excess
fermions for the two-component Tomonaga-Luttinger liquid (TLL) phase. The ratio
exhibits anomalous enhancement at the two critical points due to the sudden
change in the density of states. Despite a breakdown of the quasiparticle
description in one dimension, two important features of the Fermi liquid are
retained, namely the specific heat is linearly proportional to temperature
whereas the susceptibility is independent of temperature. In contrast to the
phenomenological TLL parameter, the Wilson ratio provides a powerful parameter
for testing universal quantum liquids of interacting fermions in one, two and
three dimensions.Comment: 5+2 pages, 4+1 figures, Eq. (4) is proved, figures were refine
Exactly solvable models and ultracold Fermi gases
Exactly solvable models of ultracold Fermi gases are reviewed via their
thermodynamic Bethe Ansatz solution. Analytical and numerical results are
obtained for the thermodynamics and ground state properties of two- and
three-component one-dimensional attractive fermions with population imbalance.
New results for the universal finite temperature corrections are given for the
two-component model. For the three-component model, numerical solution of the
dressed energy equations confirm that the analytical expressions for the
critical fields and the resulting phase diagrams at zero temperature are highly
accurate in the strong coupling regime. The results provide a precise
description of the quantum phases and universal thermodynamics which are
applicable to experiments with cold fermionic atoms confined to one-dimensional
tubes.Comment: based on an invited talk at Statphys24, Cairns (Australia) 2010. 16
pages, 6 figure
Universal local pair correlations of Lieb-Liniger bosons at quantum criticality
The one-dimensional Lieb-Liniger Bose gas is a prototypical many-body system
featuring universal Tomonaga-Luttinger liquid (TLL) physics and free fermion
quantum criticality. We analytically calculate finite temperature local pair
correlations for the strong coupling Bose gas at quantum criticality using the
polylog function in the framework of the Yang-Yang thermodynamic equations. We
show that the local pair correlation has the universal value in the quantum critical regime, the TLL phase and the
quasi-classical region, where is the pressure per unit length rescaled by
the interaction energy with interaction
strength and linear density . This suggests the possibility to test
finite temperature local pair correlations for the TLL in the relativistic
dispersion regime and to probe quantum criticality with the local correlations
beyond the TLL phase. Furthermore, thermodynamic properties at high
temperatures are obtained by both high temperature and virial expansion of the
Yang-Yang thermodynamic equation.Comment: 8 pages, 6 figures, additional text and reference
Universal behavior of giant electroresistance in epitaxial La0.67Ca0.33MnO3 thin films
We report a giant resistance drop induced by dc electrical currents in
La0.67Ca0.33MnO3 epitaxial thin films. Resistance of the patterned thin films
decreases exponentially with increasing current and a maximum drop shows at the
temperature of resistance peak Tp. Variation of resistance with current
densities can be scaled below and above Tp, respectively. This work can be
useful for the future applications of electroresistance.Comment: 13 pages, 4 figure
Promotion of cooperation induced by nonlinear attractive effect in spatial Prisoner's Dilemma game
We introduce nonlinear attractive effects into a spatial Prisoner's Dilemma
game where the players located on a square lattice can either cooperate with
their nearest neighbors or defect. In every generation, each player updates its
strategy by firstly choosing one of the neighbors with a probability
proportional to denoting the attractiveness of the
neighbor, where is the payoff collected by it and
(0) is a free parameter characterizing the extent of the nonlinear
effect; and then adopting its strategy with a probability dependent on their
payoff difference. Using Monte Carlo simulations, we investigate the density
of cooperators in the stationary state for different values of
. It is shown that the introduction of such attractive effect
remarkably promotes the emergence and persistence of cooperation over a wide
range of the temptation to defect. In particular, for large values of ,
i.e., strong nonlinear attractive effects, the system exhibits two absorbing
states (all cooperators or all defectors) separated by an active state
(coexistence of cooperators and defectors) when varying the temptation to
defect. In the critical region where goes to zero, the extinction
behavior is power law-like , where the
exponent accords approximatively with the critical exponent
() of the two-dimensional directed percolation and depends
weakly on the value of .Comment: 7 pages, 4 figure
The Heine-Stieltjes correspondence and the polynomial approach to the standard pairing problem
A new approach for solving the Bethe ansatz (Gaudin-Richardson) equations of
the standard pairing problem is established based on the Heine-Stieltjes
correspondence. For pairs of valence nucleons on different
single-particle levels, it is found that solutions of the Bethe ansatz
equations can be obtained from one (k+1)x(k+1) and one (n-1)x(k+1) matrices,
which are associated with the extended Heine-Stieltjes and Van Vleck
polynomials, respectively. Since the coefficients in these polynomials are free
from divergence with variations in contrast to the original Bethe ansatz
equations, the approach thus provides with a new efficient and systematic way
to solve the problem, which, by extension, can also be used to solve a large
class of Gaudin-type quantum many-body problems and to establish a new
efficient angular momentum projection method for multi-particle systems.Comment: ReVTeX, 4 pages, no figur
Decreased TRPM7 inhibits activities and induces apotosis of bladder cancer cells via ERK1/2 pathway
published_or_final_versio
Integrable variant of the one-dimensional Hubbard model
A new integrable model which is a variant of the one-dimensional Hubbard
model is proposed. The integrability of the model is verified by presenting the
associated quantum R-matrix which satisfies the Yang-Baxter equation. We argue
that the new model possesses the SO(4) algebra symmetry, which contains a
representation of the -pairing SU(2) algebra and a spin SU(2) algebra.
Additionally, the algebraic Bethe ansatz is studied by means of the quantum
inverse scattering method. The spectrum of the Hamiltonian, eigenvectors, as
well as the Bethe ansatz equations, are discussed
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