Amplitude-squared squeezing of superposition of coherent states

This paper discusses the amplitude-squared squeezing for the superposition of two coherent states with their phase differences being separately π/2, 3π/2, and π1, as well as for the superposition state of two pseudoclassical states. According to the analysis, it is found that the superposition state of two coherent states with their phase differences π/2 and 3π/2, and the superposition state of two pseudoclassical states both do exhibit the amplitude-squared squeezing. Also, some specific states are found to exhibit even stronger squeezing effects when relative phase of the superposition is equal to the average photon number. Amplitude-squared squeezing is dependent on the difference in phase between two coherent states.

Creation of Coherent Superposition States in Multilevel Systems

A powerful approach to generate multilevel superposition state in A-type manifold of levels is proposed. In the analysis, we introduce a group of rotations to transform the coupled system to a simpler form, which involves one coupled and several decoupled, dark states in the ground state manifold. Then an arbitrary superposition state of initial and final states can be created. In particular, when the Rabi frequencies of the Stokes pulses have equal magnitudes, a superposition state （equal population of the （n - 2） superposition states） will be generated. A numerical simulation of coherence generation is given. It is shown that a small transient population in metastable state decreases as the intensity of Stokes pulses increases. Experimental implementation in Neon atom is given.

Generation of superpositions of coherent states for an atomic sample in cavity QED

This paper proposes a scheme for generation of superpositions of coherent states of the effective bosonic mode in a collection of atoms. In the scheme an atomic sample interacts with a slightly detuned cavity mode and a resonant strong classical field. Under ceitain conditions the atomic system evolves from a coherent state to a superposition of coherent states.

Generation of any superposition of coherent states along a straight line via resonant atom-cavity interaction

This paper proposes a scheme for generating arbitrary superpositions of several coherent states along a straight line for a cavity mode. In the scheme, several atoms are sent through a cavity initially in a strong coherent state. The superposition of several coherent states with desired coefficients may be generated if each atom is detected in the excited state after it exits the cavity. The scheme is based on resonant atom-cavity interaction and no classical field is required during and after the atom cavity interaction. Thus, the scheme is very simple and the interaction time is very short, which is important in view of decoherence.

Generation of Superpositions of Two-Mode Coherent States for the Motion of Two Trapped Ions

We propose a method for the generation of superpositions of two-mode coherent states for the center-of-mass and relative vibrational modes of two trapped ions. In the scheme the ions are driven by a single travelling-wave laser field tuned to the carrier. Then a measurement of the internal states collapses the vibrational modes to the entangled coherent state.

Preparing of coherent superposition state in serial multi-∧-type system by stimulated Raman adiabatic passage

A scheme for creating an arbitrary coherent superposition of two atomic states in serial multi-A-type system is proposed. This technique with the application of a control field is based on the existence of two degenerate dark states and their interaction. The mixing of the dark states can be controlled by changing the relative delay time of the control pulse. One can get any desired superposition by changing the delay time of the control pulse.