The low-temperature properties of the SU $(N)$ Wolff impurity model are studied via Abelian bosonization. The path integral treatment of the problem allows for an exact evaluation of low-temperature properties of the model. The single-particle Green's function is enhanced due to the presence of local correlation. The basic correlation functions such as the charge or spin correlator are also influenced by the presence of impurity, and show local Fermi liquid behavior. The x-ray absorption is affected by the presence of the local Hubbard interaction. The exponent is decreased (increased) for repulsive (attractive) interactions.The low-temperature properties of the SU$(N)$ Wolff impurity model are studied via Abelian bosonization. The path integral treatment of the problem allows for an exact evaluation of low-temperature properties of the model. The single-particle Green's function is enhanced due to the presence of local correlation. The basic correlation functions such as the charge or spin correlator are also influenced by the presence of impurity, and show local Fermi liquid behavior. The x-ray absorption is affected by the presence of the local Hubbard interaction. The exponent is decreased (increased) for repulsive (attractive) interactions.

arXiv:cond-mat/0509407Physical Review BMar 23, 20062 citations

FERMI SYSTEMS WITH ATTRACTIVE AND REPULSIVE INTERACTIONS

M. Ya. Amus’ya

Zhur. Eksptl'. i Teoret. Fiz.Aug 1, 19610 citations

The one-particle Green functions for strongly correlated finite Fermi systems

N.U. Nazarov, О. А. Пономарев

Physics Letters AApr 1, 19923 citations

APPLICATION OF EIGENFUNCTIONAL THEORY ON QUANTUM MANY-PARTICLE SYSTEMS

Yu-Liang Liu

We first introduce the basic ingredients of the eigenfunctional theory, and show that a D-dimensional quantum many-particle system is mapped into a (D+1)-dimensional time-depending single-particle problem, and in the representation of the eigenfunctionals of the particle propagator, the particles become free. Then using this method, we study five kinds of quantum many-particle systems: interacting boson system, repulsive, attractive interacting fermion systems, Hubbard model and single-impurity scattering in one-dimensional fermion system, and demonstrate that the microscopic Bogoliubov theory and the phenomenological Bijl–Feynman theory of the bosons are closely related, and apart from an anti-symmetry factor Det ‖eikj·xl‖ the ground state wave function of the repulsive interacting fermion system has a similar form to that of the interacting boson system. Moreover, we show that the attractive interacting fermion system has a sound-type excitation spectrum like that in the interacting boson system. For one-dimensional Hubbard model we calculate the electron Green's function, and charge and spin density–density correlation functions which are consistent with the exact ones obtained by the Bethe ansatz and numerical calculations, and show that the ground state energy is increasing with U, and the electrons has single-occupied constraint in the large U limit. Finally, we demonstrate clearly the evolution of the system from its ultraviolet fixed point to infrared critical fixed point as the impurity potential increases. At the infrared critical fixed point, the fermion Green's function shows that the fermions are completely reflected on the impurity site.We first introduce the basic ingredients of the eigenfunctional theory, and show that a D-dimensional quantum many-particle system is mapped into a (D+1)-dimensional time-depending single-particle problem, and in the representation of the eigenfunctionals of the particle propagator, the particles become free. Then using this method, we study five kinds of quantum many-particle systems: interacting boson system, repulsive, attractive interacting fermion systems, Hubbard model and single-impurity scattering in one-dimensional fermion system, and demonstrate that the microscopic Bogoliubov theory and the phenomenological Bijl–Feynman theory of the bosons are closely related, and apart from an anti-symmetry factor Det ‖eikj·xl‖ the ground state wave function of the repulsive interacting fermion system has a similar form to that of the interacting boson system. Moreover, we show that the attractive interacting fermion system has a sound-type excitation spectrum like that in the interacting boson system. For one-dimensional Hubbard model we calculate the electron Green's function, and charge and spin density–density correlation functions which are consistent with the exact ones obtained by the Bethe ansatz and numerical calculations, and show that the ground state energy is increasing with U, and the electrons has single-occupied constraint in the large U limit. Finally, we demonstrate clearly the evolution of the system from its ultraviolet fixed point to infrared critical fixed point as the impurity potential increases. At the infrared critical fixed point, the fermion Green's function shows that the fermions are completely reflected on the impurity site.

International Journal of Modern Physics BOct 30, 200216 citations

Phase fluctuations and single-fermion spectral density in 2d systems with attraction

V. P. Gusynin, В. М. Локтев, Sergei G. Sharapov

The effect of static fluctuations in the phase of the order parameter on the normal and superconducting properties of a 2D system with attractive four-fermion interaction is studied. Analytic expressions for the fermion Green’s function, its spectral density, and the density of states are derived in the approximation where the coupling between the spin and charge degrees of freedom is neglected. The resulting single-particle Green’s function clearly demonstrates a non-Fermi-liquid behavior. The results show that as the temperature increases through the 2D critical temperature, the widths of the quasiparticle peaks broaden significantly.The effect of static fluctuations in the phase of the order parameter on the normal and superconducting properties of a 2D system with attractive four-fermion interaction is studied. Analytic expressions for the fermion Green’s function, its spectral density, and the density of states are derived in the approximation where the coupling between the spin and charge degrees of freedom is neglected. The resulting single-particle Green’s function clearly demonstrates a non-Fermi-liquid behavior. The results show that as the temperature increases through the 2D critical temperature, the widths of the quasiparticle peaks broaden significantly.

arXiv:cond-mat/9811207Journal of Experimental and Theoretical PhysicsJun 1, 200019 citations

THE APPLICATION OF GREEN'S FUNCTIONS TO THE QUASI-PARTICLE INTERACTIONS IN A MANY FERMION SYSTEM

Donald H. Kobe

Dissertation Abstr.May 1, 19620 citations

The low-temperature properties of the SU

(N)

Wolff impurity model are studied via Abelian bosonization. The path integral treatment of the problem allows for an exact evaluation of low-temperature properties of the model. The single-particle Green's function is enhanced due to the presence of local correlation. The basic correlation functions such as the charge or spin correlator are also influenced by the presence of impurity, and show local Fermi liquid behavior. The x-ray absorption is affected by the presence of the local Hubbard interaction. The exponent is decreased (increased) for repulsive (attractive) interactions.