麻省理工學院的研究人員表示，量子糾纏可以使原子鐘更精確，它可以幫助科學家探索諸如重力對時間的影響等問題。
麻省理工學院的研究人員設計了一種方法，他們說這種方法可以幫助建造迄今為止最精確的原子鐘。他們的方法可以幫助科學家探索諸如引力對時間流逝的影響以及時間是否會隨著宇宙變老而改變等問題。更精確的原子鐘甚至可以靈敏到探測暗物質和引力波。
研究人員在《自然》雜誌上發表了他們的發現，他們使用了一種不同於現有原子鐘的方法來實現更高的精度。它們的設計中心是量子糾纏原子，而不是測量隨機振蕩的原子。原子以一種「根據經典物理定律是不可能的」的方式相互關聯。
該團隊將350個鐿原子糾纏在一起。稀土元素的原子振蕩頻率與可見光相同，比其他原子鐘所用的元素銫每秒的頻率高出10萬倍。麻省理工學院指出，如果科學家能夠精確追蹤這些振蕩，他們「就可以利用原子來區分更小的時間間隔」。
是採用這種方法的最先進的原子鐘，它們從宇宙誕生(大約140億年前)就存在了，研究人員相信，它們的精確度將不到十分之一秒。在同樣的時間框架內，最先進的原子鐘以目前的設置會偏差大約半秒。
更新(12月18日):這篇文章的一個早期版本說，研究人員基於這種技術構建了一個原子鐘。據該團隊稱，他們的目標是建立一個這樣的時鐘，但到目前為止，「我們所做的是證明量子糾纏可以幫助建立最精確的時鐘。」
引力波，研究，原子鐘，量子糾纏，暗物質，原子鐘，糾纏原子
原文
MIT researchers show quantum entanglement could make atomic clocks more accurate
It could help scientists explore issues such as the effect of gravity on time.
MIT researchers have designed a method that they say could help build the most precise atomic clock to date. Their approach could help scientists explore questions such as the effect of gravity on the passage of time and whether time changes as the universe gets older. More accurate atomic clocks would even be sensitive enough to detect dark matter and gravitational waves.
The researchers, who published their findings in a paper in Nature, used a different method from existing atomic clocks to achieve greater accuracy. Instead of measuring randomly oscillating atoms, their design centers around quantumly entangled atoms. The atoms are correlated in a way that's "impossible according to the laws of classical physics."
The team entangled around 350 atoms of ytterbium. The rare earth element's atoms oscillate at the same frequency as visible light, or 100,000 times more often per second than cesium, the element used in other atomic clocks. If scientists can track those oscillations precisely, they "can use the atoms to distinguish ever smaller intervals of time," MIT notes.
Were the most advanced atomic clocks adapted to use this method and they'd been around since the beginning of the universe (some 14 billion years ago), researchers believe they'd be accurate to within less than a tenth of a second. The most advanced atomic clocks would be off by around half a second over the same timeframe with their current setups.
Update (12/18): An earlier version of this article said researchers built an atomic clock based on this technique. According to the team, their goal is to build one, however so far 「what we have done is a demonstration that quantum entanglement could help build the most precise clock.」