arXiv:quant-ph/0410003 · International Journal of Geometric Methods in Modern Physics
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 the 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 non-commutative differential geometry. However, a quantum diagonalization is not unique and is affected by some ambiguity arising from the non-commutativity of operators in quantum physics. Our method may open a new point of view in mathematical or quantum physics.