Ultra-Low-Power Hybrid Light-Matter Solitons
  New functionalities in nonlinear optics will require systems with giant optical nonlinearity as well as compatibility with photonic circuit fabrication techniques. Here we introduce a new platform based on strong light-matter coupling between waveguide photons and quantum-well excitons. On a sub-millimeter length scale we generate sub-picosecond bright temporal solitons at a pulse energy of only 0.5 pico-Joules. From this we deduce an unprecedented nonlinear refractive index 3 orders of magnitude larger than in any other ultrafast system. We study both temporal and spatio-temporal nonlinear effects and for the first time observe dark-bright spatio-temporal solitons. Theoretical modelling of soliton formation in the strongly coupled system confirms the experimental observations. These results show the promise of our system as a high speed, low power, integrated platform for physics and devices based on strong interactions between photons. 
L. Tinkler, P.M. Walker, D.V. Skryabin, A. Yulin, B. Royall, I.   Farrer, D.A. Ritchie, D.N. Krizhanovskii and M.S. Skolnick
nlin.PS cond-mat.mes-hall physics.optics