报告人简介:
侯晋川,太原理工大学bv1946伟德教授,博士生导师,研究方向为算子理论与算子代数、量子信息理论。曾担任山西师范大学董事长,山西省科协主席兼太原理工大学副董事长。曾获第二届中国青年科技奖,两次获得山西省科技进步一等奖,两次获得山西省自然科学二等奖。享受国务院特殊津贴,曾获山西省优秀专家、山西省第二届科技功臣、全国做出突出贡献的回国留学人员、全国优秀教师、全国五一劳动奖章、全国先进工作者、山西省特级劳模等荣誉。
报告简介:
We propose a quantification $C_\nu^{G_n}$ of $n$-mode Gaussian coherence. The value of $C_\nu^{G_n}$ only depends on the covariance matrices and displacement vectors of continuous-variable states without any optimization procedures, and thus is easily calculated. For $n=1$, $C_\nu^{G_1}$ is a proper Gaussian coherence measure of single-mode CV system. For $n\geq 2$, $C_\nu^{G_n}$ is invariant under any permutation of submodes, nonincreasing under any $n$-mode local incoherent Gaussian channels, vanishes at incoherent Gaussian states, and, satisfies the unification condition and the hierarchy condition that a multi-partite quantum correlation measure should obey. Thus $C_\nu^{G_n}$ is a multi-partite Gaussian correlation measure, which reveals, though the quantum coherence lives in single-partite systems, that the multi-mode coherence for continuous-variable systems can be regarded as a multipartite Gaussian correlation between modes, and such multi-partite Gaussian correlation is also a quantum resource. Moreover, we show that $C_\nu^{G_n}$ is completely monogamous as a multipartite Gaussian correlation measure. This means that the $n$-mode Gaussian coherence subjects to the principles of resource allocation. In addition, $C_\nu^{G_n}$ is an upper bound of the geometric-based single-mode Gaussian coherence measure $C_{\rm Bu}$ by the Bures distance at pure Gaussian states of mode $\leq 2$ and can be used to detect coherence in any $n$-mode Gaussian states more efficiently.