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).

Automated summary

Guiding many-body systems to desired states is a central challenge of modern quantum science. In this study, low-entropy quantum fluids of light were constructed in a Bose-Hubbard circuit using particle-by-particle assembly and adiabatic preparation. The results show the formation of strongly correlated fluids with entanglement and avoidance interactions.