title: Topological phase transitions and chiral inelastic transport induced by the squeezing of light.
abstract: There is enormous interest in engineering topological photonic systems. Despite intense activity, most works on topological photonic states (and more generally bosonic states) amount in the end to replicating a well-known fermionic single-particle Hamiltonian. Here we show how the squeezing of light can lead to the formation of qualitatively new kinds of topological states. Such states are characterized by non-trivial Chern numbers, and exhibit protected edge modes, which give rise to chiral elastic and inelastic photon transport. These topological bosonic states are not equivalent to their fermionic (topological superconductor) counterparts and, in addition, cannot be mapped by a local transformation onto topological states found in particle-conserving models. They thus represent a new type of topological system. We study this physics in detail in the case of a kagome lattice model, and discuss possible realizations using nonlinear photonic crystals or superconducting circuits.
authors.affiliation: Institute for Theoretical Physics, University of Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen, Germany.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Peano
authors.affiliation: Department of Physics, McGill University, 3600 rue University, Montreal, Quebec, Canada H3A 2T8.
authors.forename: Martin
authors.initials: M
authors.lastname: Houde
authors.affiliation: Institute for Theoretical Physics, University of Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Brendel
authors.affiliation: Institute for Theoretical Physics, University of Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen, Germany.|Max Planck Institute for the Science of Light, Günther-Scharowsky-Straße 1/Bau 24, 91058 Erlangen, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Marquardt
authors.affiliation: Department of Physics, McGill University, 3600 rue University, Montreal, Quebec, Canada H3A 2T8.
authors.forename: Aashish A
authors.initials: AA
authors.lastname: Clerk