Wang Ji-Suo

Quantum wavefunctions and fluctuations of mesoscopic RLC circuit

The quantum wavefunctions and the corresponding energy levels of a RLC (Resistance-Inductance-Capacity) electric circuit are obtained by using canonical quantization method and unitary transformation from the classical equation of motion. The quantum fluctuations of charge and current in an arbitrary eigenstate of the system have also been given as well as the uncertainty relation. It is showed that even if at 0 K charge and current in the circuit exhibit quantum fluctuations, which originates from fluctuations of zero point vibrations of the system.

A New Scheme of Entanglement Swapping and Disentanglement

We consider three two-level atoms (A, B, and C) initially in the W entanglement state, then one of them, C, is injected into a high-Q cavity to make resonant interaction to entangle with the other two atoms A and B that are far away from the cavity. The entanglement swapping or disentanglement can be realized by carrying out measurements on C and selecting appropriate interaction time of C with the coherent field.

Controlling dipole squeezing of two atoms inside a cavity via manipulating an atom outside the cavity

Considering that three two-level atoms are initially in the GHZ single state and two of the atoms are simultaneously put into a cavity initially in the coherent state, we investigate the dipole squeezing properties of the two atoms inside the cavity under the condition of resonant interaction. It is shown that dipole squeezing properties of the two atoms inside the cavity are strongly affected by rotation manipulating of the atom outside the cavity.

Entanglement Swapping and Disentanglement via an Entangled State of Atoms Interacting with a Cavity Field

We consider entanglement swapping and disentanglement schemes via an entangled state of three two-level atoms interacting with a coherent field. When a two-level atom C, entangled with two other two-level atoms A and B, is injected into a high-Q cavity and atoms A and B are far away from the cavity, the entanglement swapping or disentanglement can be realized by carrying out the measurement on the atom C and by selecting an appropriate interaction time of atom C with the coherent field.

Quantum Statistical Properties of Even and Odd qs-Coherent States*

In this paper, we use the numerical method to study the influences of and deformations on the quantum statistical properties of even and odd qs-coherent states. It is shown that nonclassical properties of the even and odd qs-coherent states are very different from those of the usual even and odd coherent states. It is found that squeezing and antibunching effect appear for both even and odd qs-coherent states in some range of the parameters , and . The smaller the and are, the larger the difference between the even and odd qs-coherent states and the usual even and odd coherent states is.

A new kind of kappa-quantum nonlinear coherent states: Their generation and physical meaning

A new kind of k-quantum nonlinear coherent states, i.e., the k eigenstates of the k-th power B-k (k greater than or equal to 3) of the generalized annihilation operator B = a1/f(N) of f-oscillators, are obtained and their properties are discussed. The completeness of the k states is investigated. An alternative method to construct them is proposed. It is shown that these states may form a complete Hilbert space, and all of them can be generated by a linear superposition of k Roy-type nonlinear coherent states. Physically, they can be generated by a linear superposition of the time-dependent Roy-type nonlinear coherent states at different instants.