Researchers have experimentally realized the Haldane model using ultracold fermions in a periodically modulated optical honeycomb lattice. The model, which describes a quantum Hall effect without an external magnetic field, relies on breaking time-reversal and inversion symmetries. Time-reversal symmetry is broken by introducing complex next-nearest-neighbour tunneling terms through circular modulation of the lattice, while inversion symmetry is broken by creating an energy offset between sublattices. These symmetries lead to a topological band structure with a Chern number, indicating a topological phase transition between trivial and Chern-insulating regimes. The experiment confirms the existence of a topological phase transition by observing the closing of a gap at a Dirac point, and the resulting Berry curvature, which gives rise to a Hall-like drift. The study also demonstrates the ability to dynamically tune topological properties and extends the model to spin-dependent Hamiltonians. The results are compared with theoretical predictions using Floquet theory, and the approach is shown to be applicable to interacting fermionic systems. The experiment provides insights into topological insulators and superconductors, and opens the possibility of studying topological models with interactions in a controlled manner.Researchers have experimentally realized the Haldane model using ultracold fermions in a periodically modulated optical honeycomb lattice. The model, which describes a quantum Hall effect without an external magnetic field, relies on breaking time-reversal and inversion symmetries. Time-reversal symmetry is broken by introducing complex next-nearest-neighbour tunneling terms through circular modulation of the lattice, while inversion symmetry is broken by creating an energy offset between sublattices. These symmetries lead to a topological band structure with a Chern number, indicating a topological phase transition between trivial and Chern-insulating regimes. The experiment confirms the existence of a topological phase transition by observing the closing of a gap at a Dirac point, and the resulting Berry curvature, which gives rise to a Hall-like drift. The study also demonstrates the ability to dynamically tune topological properties and extends the model to spin-dependent Hamiltonians. The results are compared with theoretical predictions using Floquet theory, and the approach is shown to be applicable to interacting fermionic systems. The experiment provides insights into topological insulators and superconductors, and opens the possibility of studying topological models with interactions in a controlled manner.