Disorder-assisted assembly of strongly correlated fluids of light

Abstract

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 physics³ and quantum-enhanced metrology⁴. 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 platform¹¹, 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.