Near-optimal two-mode spin squeezing via feedback

作     者：Dominic W. Berry Barry C. Sanders 

作者机构：Department of Physics and Centre for Advanced Computing–Algorithms and Cryptography Macquarie University Sydney New South Wales 2109 Australia 

出 版 物：《Physical Review A》 (物理学评论A辑：原子、分子和光学物理学)

年 卷 期：2002年第66卷第1期

页      面：012313-012313页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

主　　题：Quantum theory 

摘      要：We propose a feedback scheme for the production of two-mode spin squeezing. We determine a general expression for the optimal feedback, which is also applicable to the case of single-mode spin squeezing. The two-mode spin squeezed states obtained via this feedback are optimal for j=1/2 and are very close to optimal for j1/2. In addition, the master equation suggests a Hamiltonian that would produce two-mode spin squeezing without feedback, and is analogous to the two-axis countertwisting Hamiltonian in the single-mode case.