Comunicazione
Inducing or destroying topological phases through dissipation in open quantum systems.
Pavan F., Cataudella V. , de Candia A., De Filippis G., Di Bello G., Perroni C.A.
Manipulating topological properties of quantum matter is a key objective in condensed matter physics. A mayor role is played by the interactions, which can affect or modify topological classifications of noninteracting fermion systems in various ways. In this context, it is particularly interesting to consider a topological system coupled with the environment, that is an example of the more general class of open quantum systems. In general, these systems give rise to nontrivial physics described by an effective non-Hermitian Hamiltonian, generalizing the symmetries of topological systems and Altland-Zirnbauer classes of Hermitian Hamiltonians. We consider the well-known SSH model coupled with the environment (described as many independent phonons) through one of the two hoppings of the model. In particular we show that depending on one of the two hoppings and the strength of electron-phonon coupling one can either turn a trivial phase into a topological one or, vice versa, using the interaction within the environment, also inducing an effective non-Hermitian physics. In this way we prove that dissipation is not only detrimental to topology, but can be used to tunate topological phases.