Coherent States (Quasi-Classical States)

Osamu Hirota

Non-classical states of light field have been exploited to provide marvellous results in quantum information science. Effectiveness of nonclassical states depends on whether physical parameter as signal is continuous or digital. Here we present an investigation on the potential of quasi Bell state of entangled coherent states in quantum reading of the classical digital memory which was pioneered by Pirandola. This is a typical example of discrete quantum discrimination. We show that the quasi Bell state gives the error free performance in the quantum reading that cannot be obtained by any classical state.

S. Twareque Ali, Jean-Pierre Antoine, Jean‐Pierre Gazeau

Wei He

Based on the mean value of a mechanical quantity being a measurable value in experiment and the definition of coherent state,we discussed the charge mean value of the LC circuit and the time evolution formula of the current intensity,the wave function of coherent state and the quasi-classical wave function satisfying the Schrdinger equation.The results show the quasi-classical solution of mesoscopic circuit of charge quantization.

Piu Ghosh, Pinaki Roy

We construct quasi coherent state (QCS) of the (1+1) dimensional Dirac oscillator as eigenstates of matrix annihilation operators. It has been shown that the QCS exhibits non-classical features like quadrature squeezing. It has also been found that for a general complex coherence parameter the quadratures are correlated and the QCS satisfies Schrödinger–Robertson uncertainty relation.

Jean-Pierre Antoine, Bagarello, Fabio, Jean‐Pierre Gazeau