Zamolodchikov-Faddeev Algebra and Quantum Quenches in Integrable Field Theories

Understand

We analyze quantum quenches in integrable models and in particular the determination of the initial state in the basis of eigenstates of the post-quench hamiltonian.

• This leads us to consider the set of transformations of creation and annihilation operators that respect the Zamolodchikov-Faddeev algebra satisfied by integrable models.
• We establish that the Bogoliubov transformations hold only in the case of quantum quenches in free theories.
• In the most general case of interacting theories, we identify two classes of transformations.