时间一直以来都是一个很有意思的概念，先贤们也对此争论不休。当然，时间也在方方面面影响着人们的生活。自古就有“日出而作，日落而息”的说法。虽然来到近代，我们已经（很大程度上）脱离了日晷，摆钟，石英钟和电子表，逐渐习惯了智能手机和智能手表。我们仅需要连接网络，智能设备就可以自动设定当前的时间。而这背后，少不了一个叫做“原子钟”（Atomic clock）的设备。

原子钟可以以惊人的精度来测量时间。以1999年的数据为例，原子钟在600万年内的误差还不到一秒。而最近，一项新技术使得原子钟的精度更上一层楼。

I came cross the work Creation and manipulation of quantized vortices in Bose-Einstein condensates using reinforcement learning a few months ago and found it quite interesting.

Note added 5/28/2020: I just learnt that there’s a tool called UIUC Fellowship Finder. While completing excellent research work is the most important thing for a Ph.D. student, selling yourself is also critical to your career. Getting a fellowship from big tech companies like Google, IBM and Microsoft in the early stage of your Ph.D. study would definitely boost your future career significantly. It’s really a pit that I only get to know this when I’m about to graduating.

A few days ago, when I was browsing papers recently accepted by Phys. Rev. Lett. I noticed an interesting article Grover Search as a Naturally Occurring Phenomenon, which has just been published online today. I found this work really very fascinating, so I write this short note describing the work.

In one of my recent paper entitled Topological phases in spin-1 Fermi gases with two-dimensional spin-orbit coupling, we study the topological phases of Rashba spin-orbit (SO) coupled three-component Fermi gases. In fact, I also investigated the stability of the band crossings under repulsive $SU(3)$-invariant interactions, which is not included in the paper. In the following, I share my note on this matter.