Construction of a new class of quantum integrable inhomogeneous models
by
Anjan Kundu
Saha Institute of Nuclear Physics, Calcutta, India

Usually integrable inhomogeneous or impurity models are constructed by shifting the spectral parameter in the Lax operator. We propose a more involved and general method for such construction, in which the Lax operator involves generators of a novel quadratic algebra being a generalisation of the standard quantum algebra. In forming the monodromy matrix any number of the local Lax operators may be replaced by some with different realisations of the underlying algebra. Thus we can generate integrable inhomogeneous versions of the lattice sine-Goron, NLS, Liouville model, relativistic and nonrelativistic Toda chains etc. Following this method an interesting impure spin chain model can be constructed with an changed coupling at the impurity site.

Date received: May 27, 1998