Truncated Coherent States and Photon-Addition

Hong‐Chun Yuan, Xue-xiang Xu, Jianwen Cai +2 more

Won Sang Chung, HASSAN HASSANABADI

Abdul Q. Batin, Suranjana Ghosh, Prasanta Kumar Panigrahi +1 more

We report the close form expressions of the photon number statistics for a generalized coherent state and a generalized photon-added coherent state, which are shown to be crucial for proposing a variety of quantum scissor operations. The analytically obtained distributions are also capable of predicting the precise laser intensity windows for realizing a variety of quantum scissors. Truncating a photon added state overcomes the selection rule of obtaining the lower order Fock states. Photon addition also enables us to obtain a higher order Fock state in a lower order superposition. The importance of circular geometry is also demonstrated for engineering such quantum scissors.

Yu-Wei 煜伟 Xiao 肖, Yue Ji, Jun Wei +2 more

Abstract We theoretically investigate the phase sensitivity of a truncated SU(1,1) interferometer fed with a two-mode coherent state and employing double-port homodyne detection. On the one hand, we analytically demonstrate that the two-mode coherent state provides better phase sensitivity than the single-mode coherent state. In addition, we show that the double-port homodyne detection is a quasi-optimal measurement. For a bright coherent-state input, the sensitivity of this scheme saturates the phase-sensitivity bound determined by the quantum Fisher information. On the other hand, we quantitatively illustrate the advantage of double-port homodyne detection over the single-port scheme under ideal conditions and in the presence of photon loss, respectively. Furthermore, our analysis indicates that the scheme we propose is robust against photon loss.

B. Mojaveri, Alireza Dehghani

Francisco A. Domínguez-Serna, Francisco Javier Mendieta-Jiménez, F. Rojas