Articulo
Complex modes in unstable quadratic bosonic forms
Registro en:
issn:1050-2947
issn:1094-1622
Autor
Rossignoli, Raúl Dante
Kowalski, Andrés Mauricio
Institución
Resumen
We discuss the necessity of using nonstandard boson operators for diagonalizing quadratic bosonic forms which are not positive definite and its convenience for describing the temporal evolution of the system. Such operators correspond to non-Hermitian coordinates and momenta and are associated with complex frequencies. As application, we examine a bosonic version of a BCS-like pairing Hamiltonian, which, in contrast with the fermionic case, is stable just for limited values of the gap parameter and requires the use of the present extended treatment for a general diagonal representation. The dynamical stability of such forms and the occurrence of nondiagonalizable cases are also discussed. Facultad de Ciencias Exactas