Multiphoton transition in the Tavis-Cummings model

Abstract
The Holstein-Primakoff transformation is used to transform the model of N (>1) two-level atoms collectively interacting with multiphotons of a single quantized mode of the field (the Tavis-Cummings model) into a boson-boson model. Formal solutions are obtained in the strong-coupling limit and/or the large-number-of-atoms limit. The analogy is drawn with a simple model of frequency conversion. The characteristic function in the p representation for the transformed model is calculated.