arXiv subjects
Publications and source records attributed to Yong-de Zhang.
In this paper we present an invariant perturbation theory to adiabatic process according to the concepts of adiabatic orbits, adiabatic evolution orbit and U(1)-invariant adiabatic orbit. The probabilities of keeping the adiabatic orbit in the first-order and the second-order approximation are calculated, respectively. We also give a convenient sufficient condition.
In this paper, we present an invariant perturbation theory of the adiabatic process based on the concepts of U(1)-invariant adiabatic orbit and U(1)-invariant adiabatic expansion. As its application, we propose and discuss new adiabatic approximation conditions.
We concentrate on the geometric potential in the invariant perturbation theory of quantum adiabatic process which is presented in our recent papers. It is found out to be related to the geodesic curvature of the spherical curve in 2-dimension quantum systems. We also show that the geometric potential may affect adiabatic approximation remarkably.
In this paper we show a new way to generate entanglement via two identical three-level atoms splitting in the magnetic field interacting with the cavity field. By the system we investigate, We can acquire the EPR state, multi-dimensional entangled states etc. which are more stable than usual realization by high-energy-level Rydberg atoms and we can realize the local exchange operator too. We also achieve the goal of maintaining long- time entanglement between atoms. At last, by using the procedure of local exchange, we put forward an experimental scheme for quantum feedback.
Unknown quantum pure states of arbitrary but definite S-level of a particle can be transferred onto a group of remote two-level particles through two-level EPRs as many as the number of those particles in this group. We construct such a kind of teleportation, the realization of which need a nonlocal unitary transformation to the quantum system that is made up of the s-level particle and all the two-level particles at one end of the EPRs, and measurements to all the single particles in this system. The unitary transformation to more than two particles is also written into the product form of two-body unitary transformations.