  Guiding many-body systems to desired states is a central challenge of modern
quantum science, with applications from quantum computation to many-body
physics and quantum-enhanced metrology. Approaches to solving this problem
include step-by-step assembly, reservoir engineering to irreversibly pump
towards a target state, and adiabatic evolution from a known initial state.
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 where the eigenstates are known &
localized, then adiabatically remove this disorder, allowing quantum
fluctuations to melt the photons into a fluid. Using our plat-form, we first
benchmark this lattice melting technique by building and characterizing
arbitrary single-particle-in-a-box states, then assemble multi-particle
strongly correlated fluids. Inter-site entanglement measurements performed
through single-site tomography indicate that the particles in the fluid
delocalize, while two-body density correlation measurements demonstrate that
they also avoid one another, revealing Friedel oscillations characteristic of a
Tonks-Girardeau gas. This work opens new possibilities for preparation of
topological and otherwise exotic phases of synthetic matter.
