"Non-reciprocity in near-term quantum platforms" (MCQST Colloquium) (Prof. Anushya Chandran)

Reciprocity relates cause and effect at two points in a system. In a reciprocal system, a disturbance at A is felt at B with the same intensity as a disturbance at B would be felt at A. Somewhat surprisingly, this innocuous relation has far-reaching consequences: for example, relations between transport coefficients. Breaking reciprocity breaks these relations and opens up a world of new steady-state behaviors, such as macroscopic osillations and persistent currents. Controlling non-reciprocal effects provides a short-term goal for quantum simulators in which non-reciprocity can be readily achieved using drives and dissipation, and an intriguing route to engineering devices, such as circulators and isolators, needed for future quantum technologies.