Tavis–Cummings model

In quantum optics, the Tavis–Cummings model is a theoretical model to describe an ensemble of identical two-level atoms coupled symmetrically to a single-mode quantized bosonic field. The model extends the Jaynes–Cummings model to larger spin numbers that represent collections of multiple atoms. It differs from the Dicke model in its use of the rotating-wave approximation to conserve the number of excitations of the system.

Originally introduced by Michael Tavis and Fred Cummings in 1968 to unify representations of atomic gases in electromagnetic fields under a single fully quantum Hamiltonian — as Robert Dicke had done previously using perturbation theory — the Tavis–Cummings model's restriction to a single field-mode with negligible counterrotating interactions simplifies the system's mathematics while preserving the breadth of its dynamics.

The model demonstrates superradiance, bright and dark states, Rabi oscillations and spontaneous emission, and other features of interest in quantum electrodynamics, quantum control and computation, atomic and molecular physics, and many-body physics. The model has been experimentally tested to determine the conditions of its viability, and realized in semiconducting and superconducting qubits.