Non-reciprocal quantum many-body systems: unusual entanglement and condensation phase transitions

Quantum systems featuring non-reciprocal (or direcitonal) interactions can have a wealth of surprising behaviour and phase transitions, behaviour that in many cases has no parallels in more conventional systems. In this talk, I will discuss a novel entanglement phase transition that arises in the one-dimensional bosonic Kitaev chain, a model that is the bosonic analogue of Kitaev's celebrated model of a 1D fermionic p-wave superconductor, and that has non-reciprocal properties. Surprisingly, the entanglement phase transition in this model arises without any need for postselection or even measurements. This model has recently been realized experimentally in two different platforms (optomechanics, superconducting circuits). I will also discuss surprising phase transitions occuring in driven-dissipative condensate setups where dissipation is engineered to make hopping directional.