自旋s的离散Q-和P-符号
Discrete Q- and P-symbols for spin s
摘要：
引入相干态上投影子的非正交基，展开作用在自旋s的希尔伯特空间上的厄米算符。结果表明，（2s+1）（2s +1）自旋相干态族中厄米算符A的期望值明确地决定了该算符。换句话说，知道A在单位球面上（2s+1）（2s+1）个点处的Q符号就足以恢复该算子。这提供了一种简单的方法来重建自旋的混合态，因为它的密度矩阵是明确的参数化的期望值。此外，一个离散的P-符号自然地出现，它与一个与原始基对偶的基有关。
英文摘要：
Non-orthogonal bases of projectors on coherent states are introduced to expand hermitean operators acting on the Hilbert space of a spin s. It is shown that the expectation values of a hermitean operator A in a family of (2s+1)(2s+1) spin-coherent states determine the operator unambiguously. In other words, knowing the Q-symbol of A at (2s+1)(2s+1) points on the unit sphere is already sufficient in order to recover the operator. This provides a straightforward method to reconstruct the mixed state of a spin since its density matrix is explicitly parametrized in terms of expectation values. Furthermore, a discrete P-symbol emerges naturally which is related to a basis dual to the original one.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
