Information Entropy and Squeezing of Quantum Fluctuations in a Two-Level Atom

We study the atomic squeezing in the language of the quantum information theory.A rigorous entropy uncertainty relation which suits for characterizing the squeezing of a two-level atoms is obtained,and a general definition of information entropy squeezing in the two-level atoms is given.The information entropy squeezing of two-level atoms interacting with a single-mode quantum field is examined.Our results show that the information entropy is a superior measure of the quantum uncertainty of atomic observable,also is a remarkable good precision measure of atomic squeezing.When the population difference of two-level atom is zero,the definition of atomic squeezing based on the Heisenberg uncertainty relation is trivial,while the definition of information entropy squeezing of the atom based on the entropy uncertainty relation is valid and can provide full information on the atomic squeezing in any cases.