Speaker
Description
Fermionic Symmetry Protected Topological (SPT) phases can be destroyed by spontaneous symmetry breaking. However, particularly in low dimensions, strong quantum fluctuations may destroy local order parameters and thereby, potentially restoring the SPT phase. To illustrate this phenomenon, we present a study of a model comprising SSH chains coupled to Cooper pair boxes at different fillings (half filling and quarter filling) using a combination of analytical (bosonization, renormalization group, effective field theories) and numerical (DMRG) techniques. At half-filling, our analysis reveals that, despite the absence of gap closing in mean field theory, the inclusion of strong quantum fluctuations leads to a gap closure between non-interacting topological and trivial phases, indicating a probable restoration of the Symmetry Protected Topological (SPT) phase. Furthermore, we investigate the system at quarter filling, considering its potential in quantum technologies, and find a rich phase diagram. Our results underscore the significance of accounting for quantum fluctuations in understanding the true nature of quantum systems and reveal intriguing possibilities for topological phase restoration and quantum technological advancements.
