Quantum Diagonalization Method in the Tavis–Cummings Model
Kazuyuki Fujii, Kyoko Higashida, Ryosuke Kato, Tatsuo Suzuki, Yukako Wada
Abstract
To obtain the explicit form of evolution operator in the Tavis–Cummings model we must calculate the term e−itg(S+⊗a+S−⊗a †) explicitly which is very hard. In this paper we try to make the quantum matrix A ≡ S+ ⊗ a + S − ⊗ a † diagonal to calculate e −itgA and, moreover, to know a deep structure of the model. For the case of one, two and three atoms we give such a diagonalization which is first nontrivial examples as far as we know, and reproduce the calculations of e−itgA given in quant-ph/0404034. We also give a hint to an application to a noncommutative differential geometry. However, a quantum diagonalization is not unique and is affected by some ambiguity arising from the noncommutativity of operators in quantum physics.