Ground state of XY models of interacting spins in a transverse field
Ferenc Pázmándi, Zbigniew Domański
The authors investigate the ground state of an XY model with a transverse field, characterized by an exchange matrix, whose highest eigenvalue, lambda max , is supposed to be positive and finite. They prove rigorously that for a spin S the ground state changes at the transverse field value K c =S lambda max .
Journal of Physics A Mathematical and General•Aug 7, 1993•6 citations