Controlled Quantum Secure Direct Communication with Local Separate Measurements in Cavity QED

Abstract

In this paper, we proposed an experimentally feasible new scheme for controlled quantum secure direct communication in cavity quantum electrodynamics without apparent joint Bell-state measurement. According to the results measured by the sender and the controller, the receiver can obtain different secret messages in a deterministic way using GHZ state as the quantum channel with unit successful probability if controller cooperates with it. In the communication processes, with the assistance of a strong classical driving field, the interactions between atoms and a single-mode nonresonant cavity substitute the generalized joint Bell-basis measurements. So this scheme only need separate measurements. In addition, the scheme is insensitive to the cavity decay and the thermal field. The discussion of the scheme indicates that it is simple and realizable with present technology.

Secure Quantum Dialogue via Cavity QED

“…ge eg single-mode cavities, identical to those described in Refs. [21,32,[37][38][39][40], are used for evolution of atoms. The atoms A and C are simultaneously sent into one single-mode cavity so that they simultaneously interact with it driven by a E-mail：yetianyu@mail.zjgsu.edu.cn classical field.…”

Large payload quantum steganography based on cavity quantum electrodynamics

“…Assume that 0  = . Accordingly, the evolution operator of the system in the interaction picture can be expressed as [23][24][25] ( )…”

“…Driven by a classical field, atoms B and E interact with the other single-mode cavity. Under the rotating-wave approximation, the interactive Hamiltonian between the single-mode cavity and the atoms can be expressed as [23][24][25]…”

“…As a result, the effects of cavity decay and thermal field are eliminated. Then, in the interaction picture, the effective interaction Hamiltonian H e can be described by [23][24][25] H e = (λ /2)…”