共查询到20条相似文献,搜索用时 15 毫秒
1.
Theoretical and Mathematical Physics - 相似文献
2.
The three-band Hubbard model, known also as the Emery model, is investigated in the framework of thermal Green functions. It is shown that antiferromagnetic and superconductive states can exist in this model at appropriate doping and sufficiently low temperatures. In the two-dimensional repulsive case under consideration, superconductivity turns out to be possible due to the closeness of the Fermi level to one of the energy function saddle points and the pairing occurs in channels with odd angular momenta.Deceased.Published in Teoreticheskaya i Matematicheskaya Fizika, Vol. 105, No. 1, pp. 149–162, October, 1995. 相似文献
3.
We represent the partition function of the Hubbard model with a strong Coulomb repulsion as a path integral over auxiliary Grassman variables. An approximate analysis of the phase transitions demonstrates that (1) the system is an antiferromagnetic insulator when the doping constant is small, (2) when t/U, the system is a ferromagnetic metal if U/t > 10, and a superconducting metal if U/t 10.Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 107, No. 2, pp. 269–287, May, 1996.Translated by A. M. Semikhatov. 相似文献
4.
V. G. Marikhin 《Theoretical and Mathematical Physics》2011,168(2):1041-1047
We use the method of dressing by a linear operator of general form to construct new solutions of Schrödinger-type two-dimensional equations in a magnetic field. In the case of a nonunit metric, we integrate the class of solutions that admit a variable separation before dressing. In particular, we show that the ratio of the coefficients of the differential operators in the unit metric case satisfies the Hopf equation. We establish a relation between the solutions of the two-dimensional eikonal equation with the unit right-hand side and solutions of the Hopf equation. 相似文献
5.
6.
7.
8.
9.
A. K. Arzhnikov S. G. Novokshonov S. V. Pakhomov 《Theoretical and Mathematical Physics》1993,94(3):339-344
A system of noninteracting electrons moving in a magnetic field and a field of randomly distributed impurities is considered. An exact expression is obtained for the sum of the series of maximally crossed diagrams; it is valid in an arbitrary magnetic field. It is shown that in the two-dimensional case the relative magnitude of the corrections to the conductivity due to this series reaches 60% in the center of the lower Landau sub-band.Physicotechnical Institute of the Urals Branch of the Russian Academy of Sciences. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 94, No. 3, pp. 486–495, March, 1993. 相似文献
10.
Self-consistent approximation in the Ising model of pure and dilute magnets using a pair correlation
Theoretical and Mathematical Physics - We construct a self-consistent approximation for calculating the magnetization and Curie temperature in the Ising model on an arbitrary lattice based on using... 相似文献
11.
12.
13.
V. M. Loktev V. M. Turkovsky S. G. Sharapov 《Theoretical and Mathematical Physics》1998,115(3):694-706
Using the Fröhlich Hamiltonian, we obtain self-consistent equations for the energy gap and the chemical potential. Using these equations, we can analyze the superconductivity properties of the system for an arbitrary carrier concentration. We consider weak, intermediate, and strong intermediate, and strong interactions between fermions and observe the transition from the Cooper coupling to the local-pair regime in the indirect-interaction model. 相似文献
14.
We consider two-dimensional mixed problems in an exterior domain for a semilinear strongly damped wave equation with a power-type nonlinearity |u|p. If the initial data have a small weighted energy, we shall derive a global existence and energy decay results in the case when the power p of the nonlinear term satisfies p>6. 相似文献
15.
V. N. Bobochko 《Ukrainian Mathematical Journal》1997,49(11):1735-1741
The uniform asymptotics of a solution of a system of singularly perturbed differential equations with strong turning point is constructed. We study the case where the boundary operator is analytic with respect to a small parameter. 相似文献
16.
Let A be a real square matrix, and let J? be an interval not containing an eigenvalue of A. Is A–D nonsingular for all diagonal matrices D with entries di ∈J? This holds if A is symmetric, but is not true in general. We prove a necessary condition and indicate implications for an equation with a diagonal field. 相似文献
17.
K. S. Aramyan 《Theoretical and Mathematical Physics》2008,156(1):1075-1080
We propose an analogue of a two-dimensional singular oscillator (Smorodinsky-Winternitz oscillator) on a sphere, which is
exactly solvable in the classical sense both without and with a constant magnetic field. We find the explicit classical solutions.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 156, No. 1, pp. 131–137, July, 2008. 相似文献
18.
Derivation of lower critical magnetic field for anisotropic Ginzburg-Landau model in superconductivity 总被引:1,自引:0,他引:1
In this paper, the authors discuss the vortex structure of an anisotropic Ginzburg-Landau model for superconducting thin film
proposed by Du. We obtain the estimate for the lower critical magnetic field $
H_{C_1 }
$
H_{C_1 }
which is the first critical value of h
ex
corresponding to the first phase transition in which vortices appear in the superconductor. We also find local minimizers
of the anisotropic superconducting thin film with a large parameter κ, and for the applied magnetic field near the critical field we discuss the asymptotic behavior of the local minimizers. 相似文献
19.
We study a current densityelectric field formulationof Bean's model for the experimental set-up of an infinitelylong cylindrical superconductor subject to a transverse magneticfield. We introduce a fully practical finite-element approximationof the model and prove an error between the exact solution andthe approximate solution for the current density of order (h+ t)1/2. Numerical simulations for a variety of given sourcecurrents are presented. 相似文献
20.
V. I. Derguzov 《Journal of Mathematical Sciences》2000,98(6):679-683
An integral equation describing oscillations of a two-dimensional periodic lightguide is studied. The integral operator is
an analytic function of a spectral parameter. The homogenous integral equation has only the zero solution for all values of
the spectral parameter expect for some isolated values. Bibliography: 9 titles.
Translated fromProblemy Matematicheskogo Analiza, No. 18, 1998, pp. 78–84. 相似文献