Regensburg 2002 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 7: Postersitzung I: Anwendungen der Supraleitung (1-6), Dünne Schichten, Josephsonkontakte, SQUIDs (7-17), Neue und unkonv. Supraleiter(18-23), Amorphe- und Tunnelsyst. (24-28), Quantenflüssigkeiten (29-30), Syst. korr. Elektr.: Theorie I (31-45)
TT 7.42: Poster
Montag, 11. März 2002, 14:30–18:00, A
A supersymmetric Uq[osp(2|2)]-extended Hubbard model with boundary fields — •Rudolf A. Römer1, Xi-Wen Guan1,2, Angela Foerster2, Uwe Grimm3, and Michael Schreiber1,4 — 1Institut für Physik, Technische Universität, D-09107 Chemnitz — 2Instituto de Fisica da UFRGS, Av. Bento Goncalves, 9500, Porto Alegre, 91501-970, Brazil — 3Applied Mathematics Department, Faculty of Mathematics and Computing, The Open University, Walton Hall, Milton Keynes MK7 6AA, U.K. — 4International University Bremen, D-28725 Bremen
A strongly correlated electron system associated with the quantum superalgebra Uq[osp(2|2)] is studied in the framework of the quantum inverse scattering method. By solving the graded reflection equation, two classes of boundary-reflection K-matrices leading to four kinds of possible boundary interaction terms are found. Performing the algebraic Bethe ansatz, we diagonalize the two-level transfer matrices which characterize the charge and the spin degrees of freedom, respectively. The Bethe-ansatz equations, the eigenvalues of the transfer matrices and the energy spectrum are presented explicitly. We also construct two impurities coupled to the boundaries. In the thermodynamic limit, the ground state properties and impurity effects are discussed.
[1] X.W. Guan, A. Foerster, U. Grimm, R. A. Römer, M. Schreiber, Nucl. Phys. B 618, 650 (2001).