Researchers have demonstrated a lattice version of a fractional quantum Hall (FQH) state using a programmable on-chip platform based on photon blockade and engineered gauge fields in a two-dimensional circuit quantum electrodynamics (QED) system. This achievement represents a significant advancement in the bottom-up creation and manipulation of novel strongly correlated topological quantum matter composed of photons. The study shows that FQH states can be realized without external magnetic fields, enabling local and coherent manipulation of these exotic states. The team observed the effective photon Lorentz force and butterfly spectrum in an artificial gauge field, which are prerequisites for FQH states. After adiabatic assembly of a Laughlin FQH wavefunction with a 1/2 filling factor, they observed strong density correlations and chiral topological flow among the FQH photons. The study verified the unique features of FQH states in response to external fields, including incompressibility of generating quasiparticles and the smoking-gun signature of fractional quantum Hall conductivity. The work also demonstrated the fractional response to external fields, showing the incompressibility of the FQH liquid due to the energy gap and the existence of fractional quantum Hall conductivity. The results indicate that the photon FQH state exhibits topological properties, with the ground state being topologically trivial for magnetic flux less than 0.2 and nontrivial for magnetic flux greater than 0.2. The study also characterized the ground-state wavefunctions, showing unique spatial characteristics such as density correlation and density currents between the normal state and the photon FQH state. The results suggest that the photon FQH state has potential applications in fault-tolerant quantum information devices. The study provides a novel approach to the experimental realization of artificial lattice systems, using circuit QED techniques, and opens up possibilities for exploring new strongly interacting topological quantum matter made of photons. The work highlights the potential of circuit QED lattices for exploring new strongly interacting topological quantum matter and practical applications in topological quantum computing.Researchers have demonstrated a lattice version of a fractional quantum Hall (FQH) state using a programmable on-chip platform based on photon blockade and engineered gauge fields in a two-dimensional circuit quantum electrodynamics (QED) system. This achievement represents a significant advancement in the bottom-up creation and manipulation of novel strongly correlated topological quantum matter composed of photons. The study shows that FQH states can be realized without external magnetic fields, enabling local and coherent manipulation of these exotic states. The team observed the effective photon Lorentz force and butterfly spectrum in an artificial gauge field, which are prerequisites for FQH states. After adiabatic assembly of a Laughlin FQH wavefunction with a 1/2 filling factor, they observed strong density correlations and chiral topological flow among the FQH photons. The study verified the unique features of FQH states in response to external fields, including incompressibility of generating quasiparticles and the smoking-gun signature of fractional quantum Hall conductivity. The work also demonstrated the fractional response to external fields, showing the incompressibility of the FQH liquid due to the energy gap and the existence of fractional quantum Hall conductivity. The results indicate that the photon FQH state exhibits topological properties, with the ground state being topologically trivial for magnetic flux less than 0.2 and nontrivial for magnetic flux greater than 0.2. The study also characterized the ground-state wavefunctions, showing unique spatial characteristics such as density correlation and density currents between the normal state and the photon FQH state. The results suggest that the photon FQH state has potential applications in fault-tolerant quantum information devices. The study provides a novel approach to the experimental realization of artificial lattice systems, using circuit QED techniques, and opens up possibilities for exploring new strongly interacting topological quantum matter made of photons. The work highlights the potential of circuit QED lattices for exploring new strongly interacting topological quantum matter and practical applications in topological quantum computing.