Disorder-assisted assembly of strongly correlated fluids of light.

Guiding many-body systems to desired states is a central challenge of modern quantum science, with applications from quantum computation 1,2 to many-body physics 3 and quantum-enhanced metrology 4 . Approaches to solving this problem include step-by-step assembly 5,6 , reservoir engineering to irreversibly pump towards a target state 7,8 and adiabatic evolution from a known initial state 9,10 . Here we construct low-entropy quantum fluids of light in a Bose-Hubbard circuit by combining particle-by-particle assembly and adiabatic preparation. We inject individual photons into a disordered lattice for which the eigenstates are known and localized, then adiabatically remove this disorder, enabling quantum fluctuations to melt the photons into a fluid. Using our platform 11 , we first benchmark this lattice melting technique by building and characterizing arbitrary single-particle-in-a-box states, then assemble multiparticle strongly correlated fluids. Intersite entanglement measurements performed through single-site tomography indicate that the particles in the fluid delocalize, whereas two-body density correlation measurements demonstrate that they also avoid one another, revealing Friedel oscillations characteristic of a Tonks-Girardeau gas 12,13 . This work opens new possibilities for the preparation of topological and otherwise exotic phases of synthetic matter 3,14,15 .