By adding some magnetic flair to an exotic quantum experiment, physicists produced an ultra-stable one-dimensional quantum gas with never-before-seen “scar” states – a feature that could someday be useful for securing quantum information.
通过在量子实验中加入一些磁性元素，物理学家们制造出了一种超稳定的一维量子气体，这种气体具有前所未见的“伤疤”状态——这一特性有朝一日可能会用于保护量子信息。
As the story goes, the Greek mathematician and tinkerer Archimedes came across an invention while traveling through ancient Egypt that would later bear his name. It was a machine consisting of a screw housed inside a hollow tube that trapped and drew water upon rotation. Now, researchers led by Stanford University physicist Benjamin Lev have developed a quantum version of Archimedes’ screw that, instead of water, hauls fragile collections of gas atoms to higher and higher energy states without collapsing. Their discovery is detailed in a paper published today (January 14, 2021) inScience.
据说，希腊数学家和发明家阿基米德在古埃及旅行时偶然发现了一项发明，这项发明后来以他的名字命名。这是一种由一个螺丝组成的机器，它被安装在一个中空的管子里，在旋转的过程中收集和吸取水分。现在，由斯坦福大学物理学家本杰明 · 列夫领导的研究人员已经开发出一种量子版的阿基米德螺旋，这种螺旋代替了水，将脆弱的气体原子集合带到越来越高的能量状态而不会坍塌。他们的发现详见今天(2021年1月14日)发表在《科学》杂志上的一篇论文。
“My expectation for our system was that the stability of the gas would only shift a little,” said Lev, who is an associate professor of applied physics and of physics in the School of Humanities and Sciences at Stanford. “I did not expect that I would see a dramatic, complete stabilization of it. That was beyond my wildest conception.”
“我对我们的系统的预期是，气体的稳定性只会发生一点点变化，” Lev 说，他是斯坦福大学人文与科学学院的应用物理学和物理学副教授。“我没有预料到它会戏剧性地完全稳定下来。这超出了我最疯狂的想象。”
Along the way, the researchers also observed the development of scar states – extremely rare trajectories of particles in an otherwise chaotic quantum system in which the particles repeatedly retrace their steps like tracks overlapping in the woods. Scar states are of particular interest because they may offer a protected refuge for information encoded in a quantum system. The existence of scar states within a quantum system with many interacting particles – known as a quantum many-body system – has only recently been confirmed. The Stanford experiment is the first example of the scar state in a many-body quantum gas and only the second ever real-world sighting of the phenomenon.
在这个过程中，研究人员还观察到了疤痕状态的发展——在另一个混沌的量子系统中，极其罕见的粒子轨迹。在这个量子系统中，粒子反复追踪它们的轨迹，就像树林中的轨迹重叠一样。疤痕态特别有趣，因为它们可以为量子系统中编码的信息提供一个受保护的避难所。量子系统中存在着许多相互作用的粒子——被称为量子多体系统——直到最近才被证实。斯坦福的实验是多体量子气体中疤痕态的第一个例子，也是有史以来第二次在现实世界中看到这种现象。
Lev specializes in experiments that extend our understanding of how different parts of a quantum many-body system settle into the same temperature or thermal equilibrium. This is an exciting area of investigation because resisting this so-called “thermalization” is key to creating stable quantum systems that could power new technologies, such as quantum computers.
Lev 专门从事扩展我们对量子多体系统不同部分如何适应相同温度或热平衡的理解的实验。这是一个令人兴奋的研究领域，因为抵抗这种所谓的“热化”是创造稳定的量子系统的关键，这种系统可以为新技术(如量子计算机)提供动力。
In this experiment, the team explored what would happen if they tweaked a very unusual many-body experimental system, called a super Tonks-Girardeau gas. These are highly excited one-dimensional quantum gases – atoms in a gaseous state that are confined to a single line of movement – that have been tuned in such a way that their atoms develop extremely strong attractive forces to one another. What’ssuper about them is that, even under extreme forces, they theoretically should not collapse into a ball-like mass (like normal attractive gases will). However, in practice, they do collapse because of experimental imperfections. Lev, who has a penchant for the strongly magnetic element dysprosium, wondered what would happen if he and his students created a super Tonks–Girardeau gas with dysprosium atoms and altered their magnetic orientations ‘just so.’ Perhaps they would resist collapse just a little bit better than nonmagnetic gases?
在这个实验中，研究小组探索了如果他们调整一个非常不寻常的多体实验系统，称为超级唐克斯-吉拉多气体会发生什么。这些是高度激发的一维量子气体——处于气态的原子仅限于单一运动轨迹——它们的原子之间产生了极强的相互吸引力。它们的超级之处在于，即使在极端的外力作用下，理论上它们也不会坍缩成球状的质量(就像普通的吸引气体一样)。然而，在实践中，它们确实会因为实验缺陷而倒塌。对强磁性元素镝情有独钟的 Lev 想知道，如果他和他的学生用镝原子创造出一种超级 Tonks-Girardeau 气体，并改变它们的磁场方向，会发生什么。也许它们能比非磁性气体更好地抵抗坍塌？
“The magnetic interactions we were able to add were very weak compared to the attractive interactions already present in the gas. So, our expectations were that not much would change. We thought it would still collapse, just not quite so readily,” said Lev, who is also a member ofStanford Ginzton Lab and Q-FARM . “Wow, were we wrong.”
“与气体中已经存在的吸引力相比，我们能够添加的磁相互作用非常微弱。所以，我们的期望是不会有太大的改变。我们认为它仍然会崩溃，只是不是那么容易，” Lev 说，他也是 Stanford Ginzton 实验室和 Q-FARM 的成员。“哇，我们错了。”
Their dysprosium variation ended up producing a super Tonks–Girardeau gas that remained stable no matter what. The researchers flipped the atomic gas between the attractive and repulsive conditions, elevating or “screwing” the system to higher and higher energy states, but the atoms still didn’t collapse.
他们的镝变异最终产生了一种无论如何都保持稳定的超级 Tonks-Girardeau 气体。研究人员将原子气体在吸引力和排斥力之间转换，使系统升高或“旋转”到能量越来越高的状态，但原子仍然没有崩溃。
While there are no immediate practical applications of their discovery, the Lev lab and their colleagues are developing the science necessary to power that quantum technology revolution that many predict is coming. For now, said Lev, the physics of quantum many-body systems out of equilibrium remain consistently surprising.
虽然他们的发现还没有直接的实际应用，但 Lev 实验室和他们的同事们正在开发必要的科学，以推动许多人预测即将到来的量子技术革命。现在，Lev 说，量子多体系统失去平衡的物理学仍然一直令人惊讶。
“There’s no textbook yet on the shelf that you can pull off to tell you how to build your own quantum factory,” he said. “If you compare quantum science to where we were when we discovered what we needed to know to build chemical plants, say, it’s like we’re doing the late 19th-century work right now.”
他说: “现在还没有教科书可以告诉你如何建立自己的量子工厂。”。“如果你把量子科学与我们发现建造化工厂所需知识时的情况相比较，就好像我们现在正在做19世纪末的工作。”
These researchers are only beginning to examine the many questions they have about their quantum Archimedes’ screw, including how to mathematically describe these scar states and if the system does thermalize – which it must eventually – how it goes about doing that. More immediately, they plan to measure the momentum of the atoms in the scar states to begin to develop a solid theory about why their system behaves the way it does.
这些研究人员只是刚刚开始研究他们对量子阿基米德螺钉的许多疑问，包括如何用数学方法描述这些疤痕状态，以及系统是否会热化——最终必然会热化——它是如何做到的。更直接的是，他们计划测量疤痕状态的原子的动量，开始发展一个关于他们的系统为什么会这样运作的可靠理论。
The results of this experiment were so unanticipated that Lev says he can’t strongly predict what new knowledge will come from deeper inspection of the quantum Archimedes’ screw. But that, he points out, is perhaps experimentalism at its best.
这个实验的结果是如此出乎意料，以至于 Lev 说他无法有力地预测通过对量子阿基米德螺旋进行更深入的检查会得到什么样的新知识。但是，他指出，这也许是实验主义最好的一面。
“This is one of the few times in my life where I’ve actually worked on an experiment that was truly experimental and not a demonstration of existing theory. I didn’t know what the answer would be beforehand,” said Lev. “Then we found something that was truly new and unexpected and that makes me say, ‘Yay experimentalists!’”
“这是我人生中为数不多的几次真正从事一项实验的机会之一，这项实验是真正的实验，而不是现有理论的演示。我事先不知道答案会是什么。”。“然后我们发现了一些真正意想不到的新东西，这让我说，‘耶，实验者！”’
Reference: 14 January 2021,Science .
参考文献: 14 January 2021，Science。
Additional Stanford authors are graduate students Wil Kao (co-lead author), Kuan-Yu Li (co-lead author) and Kuan-Yu Lin. A professor from CUNY College of Staten Island and CUNY, New York, is also a co-author. Lev is also a member of Stanford Bio-X .
其他斯坦福大学的作者是研究生高威尔(合著者) ，李宽玉(合著者)和林。来自纽约市立大学史坦顿岛和纽约市立大学的教授也是合著者。Lev 也是 Stanford Bio-X 的成员。
This research was funded by the National Science Foundation, Air Force Office of Scientific Research, Natural Sciences and Engineering Research Council of Canada and the Olympiad Scholarship from the Taiwan Ministry of Education.
本研究由国家科学基金会、加拿大空军科学研究办公室、自然科学与工程研究委员会及台湾教育部奥林匹克奖学金资助。
本文来自Scitechdaily，如有侵权请在“我的页面”联系我们
联系客服
