时间晶体的最新突破,是一种不需要外部输入的结构
A newly theorised type of time crystal could revolutionise the potential of these fascinating structures. Unlike the time crystals that have been created to date, it would not require the application of an external stimulus to keep the atoms ticking.
一种新理论的时间晶体可能彻底改变这些迷人结构的潜力。与迄今为止所创造的时间晶体不同，它不需要外部刺激来维持原子的运转。
The method hinges on inducing entangled particles to affect each other's 'spin' (a property like angular momentum) over a distance. But to understand the details of this latest approach, first we need to step back a little.
这种方法的关键在于诱导相互纠缠的粒子在一定距离内影响彼此的“自旋”(一种类似角动量的性质)。但要了解这一最新方法的细节，我们首先需要后退一步。
Time crystals may sound like some wacky sci-fi concept, but they're a real phenomenon, first theorised in 2012. From the outside, they look just like normal crystals. But inside, the atoms - arranged in an otherwise normal repeating lattice structure - are behaving quite peculiarly.
时间晶体可能听起来像某种古怪的科幻概念，但它们是一种真实的现象，2012年首次提出理论。从外面看，它们就像普通的晶体。但在内部，原子——以正常的重复晶格结构排列——表现得相当奇特。
To date, time crystals produced experimentally have required an external stimulus (such as a pulse of electromagnetic radiation) at ground state, or lowest-energy state, to induce their ticking. This was achieved in 2016, but since then, there has been debate over whether this fits what we imagine a real time crystal to be like.
到目前为止，实验产生的时间晶体需要在基态或最低能量态的外部刺激(如电磁辐射脉冲)来诱发滴答声。这是在2016年实现的，但从那以后，关于这是否符合我们对真实时间水晶的想象，一直存在争议。
In fact, it has seemed very much that time crystals without an energy input to its ground state are simply physically impossible, according to a 2015 paper. In physics this is known as a no-go theorem.
事实上，根据2015年的一篇论文，没有能量输入到基态的时间晶体在物理上几乎是不可能的。在物理学中，这被称为“不走”定理。
According to the physicists, in time crystals such interaction-at-a-distance could theoretically produce a time crystal ground state that needs no energy injection.
根据物理学家的说法，在时间晶体中，这种距离上的相互作用理论上可以产生一种不需要能量注入的时间晶体基态。
In their new paper, they propose a system of particles within the time crystal, each of which has a spin. They demonstrate that there is a way to describe the entangled particles' spins using a string theory model that meets the 2015 paper's definition of a time crystal.
在他们的新论文中，他们提出了一个时间晶体内的粒子系统，每个粒子都有自旋。他们证明，有一种方法可以用弦理论模型描述纠缠粒子的自旋，该模型符合2015年论文对时间晶体的定义。
Even if the particles were spinning out of sync, the interactions between the particles would produce the ticking of a time crystal, according to the researchers.
研究人员表示，即使粒子旋转不同步，粒子之间的相互作用也会产生时间晶体的滴答声。
Now, this system would be incredibly complicated, with each particle able to spin in superposition - that is, in an undetermined state of both up and down at the same time.
现在，这个系统会变得非常复杂，每个粒子都可以在叠加状态下自旋，也就是说，同时处于一种向上和向下的未知状态。
In fact, the whole thing might not be feasible to create in a lab setting. Entangling particles in this manner is an idea that works well on paper, but is unlikely to be easily doable practically.
事实上，在实验室环境中创造整个东西可能是不可行的。以这种方式缠绕粒子的想法在纸面上很有效，但在实际中不太可能轻易实现。
