DIAGONALIZATION OF A BOSONIC QUADRATIC FORM USING CCM: APPLICATION ON A SYSTEM WITH TWO INTERPENETRAING SQUARE LATTICE ANTIFERROMAGNETS

摘要

While the diagonalization of a quadratic bosonic form can always be done using a Bogolyubov transformation, the practical implementation for systems with a large number of different bosons is a tedious analytical task. Here we use the couple cluster method to exactly diagonalise such com- Plicated quadratic forms.