Symmetry breaking: balancing asymmetries

Spontaneous symmetry breaking (SSB) is a ubiquitous natural phenomenon where a system characterized by certain symmetries can evolve into a state that does not exhibit those symmetries. SSB underpins many fundamental phenomena, including phase transitions in meta-materials or Bose-Einstein condensates, the emergence of the Nambu-Goldstone and Higgs modes of crucial importance in particle physics, or bifurcations in lasers, and could have significant applications, especially in photonics. Physical systems however often exhibit deviations from perfect symmetry because of naturally occurring imperfections. How small asymmetries affect SSB-related dynamics is therefore an important problem. Surprisingly, this has barely been considered in experiments, and even then restricted to situations with only one asymmetry parameter [1]. Here, we report spontaneous breaking of a mirror symmetry in an optical experiment with two controllable asymmetry parameters. Specifically, we explore how controlled asymmetries affect the range of co-existence of two homogeneous states (HSs) with different polarizations in a driven Kerr resonator, and discover that different asymmetries can compensate for each other.