  Superconducting qubits provide a competitive platform for quantum simulation
of complex dynamics that lies at the heart of quantum many-body systems,
because of the flexibility and scalability afforded by the nature of
microfabrication. However, in a multiqubit device, the physical form of
couplings between qubits is either an electric (capacitor) or magnetic field
(inductor), and the associated quadratic field energy determines that only
two-body interaction in the Hamiltonian can be directly realized. Here we
propose and experimentally synthesize the three-body spin-chirality interaction
in a superconducting circuit based on Floquet engineering. By periodically
modulating the resonant frequencies of the qubits connected with each other via
capacitors, we can dynamically turn on and off qubit-qubit couplings, and
further create chiral flows of the excitations in the three-qubit circular
loop. Our result is a step toward engineering dynamical and many-body
interactions in multiqubit superconducting devices, which potentially expands
the degree of freedom in quantum simulation tasks.
