Exploring non-equilibrium phases of matter using controlled quantum systems

Advances in quantum technologies are pushing towards building complex quantum systems from individual atoms, ions, photons, and solid-state qubits. The engineered quantum many-body systems are often constantly driven by external fields and always in contact with external bath. Together with a great degree of controllability for microscopic interactions, they offer an ideal platform to explore non-equilibrium phases of light and matter in driven and open settings, about which little is known. The biggest challenge in this endeavour however lies at the difficulty of scaling up the system size while maintaining controllability.
In this talk, I will introduce an approach that circumvents the issue of scalability based on the notion of finite-component system phase transition, thereby allowing the realization of non-equilibrium phases of matter with controlled quantum systems that are currently available in labs. I will show how the simultaneously large spin-boson coupling strength and detuning lead to the thermodynamic limit of infinite boson excitations in which finite-component systems could undergo a phase transition and how such an exotic limit can be engineered in physical systems such as ion-traps. I will discuss the prospects of finite-component system phase transitions as a general framework to advance our understanding of non-equilibrium phases of matter and give concrete examples ranging from dissipative phase transition to Kibble-Zurek mechanism.