Quantum ‘Jamming’ Explores the Truly Fundamental Principles of Nature

Samuel Velasco/ Quanta Magazine

塞缪尔·贝拉斯科/广达杂志

For the past few decades, researchers have understood that quantum computers should eventually be able to crack the widely used codes that secure much of the digital world.

在过去的几十年里，研究人员已经认识到，量子计算机最终应该能够破解广泛使用的保护大部分数字世界的代码。

To protect against this fate, they’ve spent years developing new codes that appear to be safe from future safecrackers armed with quantum computers.

为了避免这种命运，他们花了数年时间开发新代码，这些代码似乎可以安全地免受未来配备量子计算机的窃贼的攻击。

At the same time, they’ve also devised ingenious ways to use the rules of quantum mechanics to keep communications secure.

与此同时，他们还设计了巧妙的方法来利用量子力学规则来保证通信安全。

But quantum mechanics, just like the “classical” mechanics that preceded it, is just a theory of nature.

但量子力学，就像它之前的“经典”力学一样，只是一种自然理论。

What if it eventually gets superseded by a fuller theory, just as quantum mechanics supplanted Newtonian physics a century ago?

如果它最终被更全面的理论取代，就像一个世纪前量子力学取代牛顿物理学一样，会怎样？

Will these quantum communication techniques still be secure in a world where there’s an even more fundamental set of rules?

在一个存在更基本规则的世界中，这些量子通信技术仍然安全吗？

“In terms of these cryptographic protocols, it’s good to be paranoid,” said Ravishankar Ramanathan , a quantum information theorist at the University of Hong Kong who works on quantum cryptography.

“就这些加密协议而言，保持偏执是好事，”香港大学研究量子加密的量子信息理论家 Ravishankar Ramanathan 说。

“Let’s try to minimize the assumptions behind the protocol.

“让我们尽量减少协议背后的假设。

Let’s suppose that at some future date people realize that quantum mechanics is not the ultimate theory of nature.”

让我们假设在未来的某个时候，人们意识到量子力学并不是自然的终极理论。”

It’s a possibility worth considering.

这是一个值得考虑的可能性。

The difficulty of outstanding problems — like reconciling quantum mechanics and gravity — suggests that a post-quantum theory of nature might involve something quite unexpected.

诸如协调量子力学和引力之类的突出问题的难度表明，后量子自然理论可能涉及一些非常意想不到的事情。

To guard against the possibility that their protocols are based on faulty assumptions, some quantum cryptographers search for even more basic principles to build upon.

为了防止他们的协议基于错误的假设，一些量子密码学家正在寻找更基本的原理来构建。

Instead of starting from quantum mechanics, they dig deeper, down to the very concept of causality.

他们没有从量子力学开始，而是更深入地挖掘，直到因果关系的概念本身。

Ravishankar Ramanathan is a quantum information theorist at the University of Hong Kong who works on quantum cryptography.

Ravishankar Ramanathan 是香港大学的量子信息理论家，主要研究量子密码学。

Courtesy of Ravishankar Ramanathan

由拉维尚卡·拉马纳坦提供

One way to understand developments in this area is to consider quantum key distribution, which involves taking advantage of the rules of quantum mechanics to pass along a key — something that can be used to decode a secret message — in a way that cannot be covertly tampered with.

了解该领域发展的一种方法是考虑量子密钥分发，其中涉及利用量子力学规则以无法秘密篡改的方式传递密钥（可用于解码秘密消息的东西）。

Quantum key distribution makes use of quantum entanglement, which locks two particles together through one of their properties, like spin.

量子密钥分配利用量子纠缠，它通过两个粒子的一种属性（例如自旋）将它们锁定在一起。

Quantum entanglement contains something of a trip wire.

量子纠缠包含某种绊线。

If anyone tries to mess with the entanglement — as they would if they tried to steal the key — the intrusion will destroy the entanglement, revealing the sabotage.

如果有人试图扰乱纠缠——就像他们试图偷窃钥匙一样——入侵就会破坏纠缠，暴露破坏行为。

This is because of a fundamental quantum mechanical principle called the “monogamy of entanglement.”

这是因为称为“纠缠一夫一妻制”的基本量子力学原理。

But what if this principle no longer held?

但如果这个原则不再成立怎么办？

In such a case, if the people passing the message did not have complete control of their devices, an outsider could potentially subtly change the particles’ entanglement, disrupting the communication without leaving a trace.

在这种情况下，如果传递消息的人无法完全控制他们的设备，那么外人可能会巧妙地改变粒子的纠缠，从而在不留下痕迹的情况下中断通信。

This process is called quantum jamming, and efforts to understand it have surged in recent years.

这个过程被称为量子干扰，近年来了解它的努力不断增加。

For many scientists, jamming is appealing because it can help them better understand both quantum mechanics and the nature of cause and effect.

对于许多科学家来说，干扰很有吸引力，因为它可以帮助他们更好地理解量子力学和因果关系的本质。

They wonder: Are there deep principles that forbid jamming, that make it impossible?

他们想知道：是否存在禁止干扰的深刻原则，从而使干扰变得不可能？

Or, if no principle forbids it, could jamming occur in the real world?

或者，如果没有原则禁止，现实世界中是否会发生干扰？

Michał Eckstein , a theoretical physicist at the Jagiellonian University in Krakow, Poland, likes to illustrate jamming with a story.

米哈乌·埃克斯坦 (Michał Eckstein) 是波兰克拉科夫雅盖隆大学的理论物理学家，他喜欢用故事来说明干扰。

Its protagonists are the classic characters from explanations of quantum mechanics, Alice and Bob.

它的主角是量子力学解释中的经典人物爱丽丝和鲍勃。

Will these quantum communication techniques still be secure in a world where there’s an even more fundamental set of rules?

在一个存在更基本规则的世界中，这些量子通信技术仍然安全吗？

“Suppose you have Alice and Bob, and they meet a magician, Jim the Jammer,” Eckstein said.

“假设你有爱丽丝和鲍勃，他们遇到了一位魔术师，干扰者吉姆，”埃克斯坦说。

“The magician says, ‘I have two balls; one is white, and one is black.’”

“魔术师说，‘我有两个球；一个是白色的，一个是黑色的。’”

The balls stand in for a pair of entangled particles.

这些球代表一对纠缠的粒子。

If two particles are entangled, they have a property that is linked in some way — if you measure the first particle and find that its spin is up, for example, the other particle’s spin will inevitably be down, and vice versa.

如果两个粒子纠缠在一起，它们就有一个以某种方式联系在一起的属性——例如，如果你测量第一个粒子并发现它的自旋向上，那么另一个粒子的自旋将不可避免地向下，反之亦然。

This holds true even if the other particle is halfway across the universe.

即使另一个粒子横跨宇宙的一半，这也成立。

Here the balls are linked such that if one is white, the other will always be black.

这里的球是相连的，如果一个是白色的，另一个总是黑色的。

In the classic trope of stage magic, Jim lets members of the audience see the balls get placed into two boxes, mixed up, and given to Alice and Bob.

在舞台魔术的经典比喻中，吉姆让观众看到球被放入两个盒子中，混合在一起，然后交给爱丽丝和鲍勃。

No one, at this point, knows which ball is in which box.

此时，没有人知道哪个球在哪个盒子里。

Then Alice and Bob get into rocket ships that fly off in opposite directions at close to the speed of light.

然后爱丽丝和鲍勃进入火箭飞船，以接近光速向相反的方向飞行。

After a while, Alice opens her box, and Bob opens his.

过了一会儿，爱丽丝打开了她的盒子，鲍勃也打开了他的盒子。

But in the meantime, Jim has performed a trick, and the balls have changed.

但与此同时，吉姆表演了一个技巧，球已经改变了。

At first, neither Alice nor Bob notices Jim’s interference.

起初，爱丽丝和鲍勃都没有注意到吉姆的干扰。

Each expects to have a 50% chance of seeing a white or black ball, and when each opens up their box, the ball is either white or black.

每个人都期望有 50% 的机会看到白球或黑球，当每个人打开盒子时，球要么是白球，要么是黑球。

Nothing Jim does can change that.

吉姆所做的一切都无法改变这一点。

When Alice and Bob meet back on Earth, though, the magician’s trick is revealed.

然而，当爱丽丝和鲍勃回到地球时，魔术师的把戏被揭露了。

When Alice and Bob compare their measurements, they find that the balls are the same color.

当爱丽丝和鲍勃比较他们的测量值时，他们发现球的颜色相同。

Jim has shifted the nature of the balls’ entanglement — from being opposite colors to being perfect matches.

吉姆改变了球纠缠的性质——从相反的颜色变成了完美的匹配。

That’s the basic idea, though in reality the process of quantum jamming is a little more complicated.

这是基本思想，尽管实际上量子干扰的过程要复杂一些。

Mirjam Weilenmann is a researcher at the French national research institute Inria who works on quantum information and the foundations of quantum theory.

Mirjam Weilenmann 是法国国家研究所 Inria 的研究员，致力于量子信息和量子理论基础的研究。

In the mid-1990s, Jacob Grunhaus, Sandu Popescu, and Daniel Rohrlich were exploring just how far a theory could go beyond the rules of quantum mechanics while still respecting a core principle of Einstein’s: You can’t send information faster than the speed of light.

20 世纪 90 年代中期，雅各布·格伦豪斯 (Jacob Grunhaus)、桑杜·波佩斯库 (Sandu Popescu) 和丹尼尔·罗尔利希 (Daniel Rohrlich) 正在探索一种理论可以在多大程度上超越量子力学规则，同时仍然尊重爱因斯坦的核心原则：你发送信息的速度不能超过光速。

Einstein’s mid-century thought experiments showed that without this “no-signaling” principle, the very notion of cause and effect would start to fray.

爱因斯坦二十世纪中叶的思想实验表明，如果没有这种“无信号”原则，因果关系的概念就会开始出现问题。

Since then, the no-signaling principle has become a core assumption when physicists consider what might lie beyond quantum mechanics.

从那时起，无信号原理就成为物理学家考虑量子力学之外的问题时的核心假设。

“When we work in quantum foundations, what we take very seriously is the no-signaling principle,” said Mirjam Weilenmann of the French national research institute Inria.

法国国家研究所 Inria 的 Mirjam Weilenmann 表示：“当我们从事量子基础研究时，我们非常重视无信号原则。”

Grunhaus, Popescu, and Rohrlich imagined jamming as a kind of super-entanglement that could interfere with entangled particles.

格伦豪斯、波佩斯库和罗尔利希将干扰想象为一种超纠缠，可以干扰纠缠粒子。

Just as you could use a measuring device to determine the fate of a distant entangled particle, you could use a hypothetical jamming device to change the correlation between a pair of distant entangled particles.

正如您可以使用测量装置来确定远处纠缠粒子的命运一样，您可以使用假设的干扰装置来改变一对远处纠缠粒子之间的相关性。

If this jamming procedure obeyed a few key rules, some physicists argue, it would secretly disrupt quantum entanglement without disrupting causality.

一些物理学家认为，如果这种干扰程序遵循一些关键规则，它将在不破坏因果关系的情况下秘密破坏量子纠缠。

The idea of quantum jamming is so strange that initially physicists didn’t know quite what to do with it.

量子干扰的想法是如此奇怪，以至于物理学家最初不知道如何处理它。

“We wrote that paper and that was the end of it,” Popescu said.

“我们写了那篇论文，事情就这样结束了，”波佩斯库说。

Twenty years later, the time was right to explore it further.

二十年后，是时候进一步探索它了。

Quantum cryptography had grown, as quantum computers went from theoretical ideas to experiments in the real world.

随着量子计算机从理论思想走向现实世界的实验，量子密码学不断发展。

In the first decade of the 2000s, several groups developed device-independent quantum key distribution, a quantum cryptography procedure that depends on the monogamy of entanglement.

在 2000 年代的前十年，几个小组开发了与设备无关的量子密钥分发，这是一种依赖于纠缠一夫一妻制的量子密码程序。

In 2016, Ramanathan and Paweł Horodecki were thinking about these protocols when they found the paper by Grunhaus, Popescu, and Rohrlich.

2016 年，Ramanathan 和 Paweł Horodecki 发现 Grunhaus、Popescu 和 Rohrlich 撰写的论文时正在思考这些协议。

“We started to realize that this property of monogamy, upon which all of device-independent cryptography is based, completely fails once you start to allow these types of jamming correlations,” Ramanathan said.

拉马纳坦说：“我们开始意识到，一旦开始允许这些类型的干扰相关性，所有与设备无关的密码学都以此为基础的一夫一妻制特性就会完全失败。”

Soon, jamming was the subject of vigorous discussion.

很快，即兴演奏就成为了热烈讨论的话题。

Many researchers felt the thought experiment was missing something important: While jamming can’t be used to send signals faster than light, influencing the state of a distant quantum particle still feels like the kind of “spooky action at a distance” that long ago tormented Einstein.

许多研究人员认为这个思想实验遗漏了一些重要的东西：虽然干扰不能用来以比光更快的速度发送信号，但影响遥远量子粒子的状态仍然感觉像是很久以前折磨爱因斯坦的那种“幽灵般的远距离作用”。

But for some researchers, the discomfort that quantum jamming creates is inspiring new ideas.

但对于一些研究人员来说，量子干扰带来的不适正在激发新的想法。

“I see it as a tool to try to help hone our intuitions of what the right definition of causation is,” said Roger Colbeck , who proposed one of the first protocols for device-independent cryptography in his 2006 doctoral thesis.

罗杰·科尔贝克 (Roger Colbeck) 在 2006 年的博士论文中提出了第一个独立于设备的密码学协议，他说：“我认为它是一种工具，可以帮助我们磨练对因果关系正确定义的直觉。”

Now at King’s College London, Colbeck is working with V.

现在，科尔贝克在伦敦国王学院与 V.

Vilasini at Inria research center at the University of Grenoble Alpes to classify the way cause and effect work in different theories.

格勒诺布尔阿尔卑斯大学 Inria 研究中心的 Vilasini 对不同理论中因果关系的运作方式进行了分类。

For them, jamming serves as a useful edge case.

对他们来说，干扰是一种有用的边缘情况。

They’re seeking another fundamental principle, like the no-signaling principle, that explains which rules jamming breaks.

他们正在寻求另一个基本原则，比如无信号原则，来解释哪些规则会被干扰。

The groups of Ramanathan and Horodecki responded to this work, as well as a recent paper by Weilenmann, in a preprint in December 2025 that they wrote with Eckstein, Tomasz Miller, and Paweł Horodecki’s father, Ryszard.

Ramanathan 和 Horodecki 小组对这项工作以及 Weilenmann 最近在 2025 年 12 月与 Eckstein、Tomasz Miller 和 Paweł Horodecki 的父亲 Ryszard 撰写的预印本中发表的一篇论文做出了回应。

Now, the researchers are in conversation, trying to clarify terms, fix misunderstandings, and look for the fundamental principles behind physical theories.

现在，研究人员正在进行对话，试图澄清术语，消除误解，并寻找物理理论背后的基本原理。

“That’s for me the most interesting question,” Eckstein said.

“这对我来说是最有趣的问题，”埃克斯坦说。

“Is there any new physics behind it?

“这背后有什么新的物理原理吗？

Can physics include such phenomena?”

物理学能包含这样的现象吗？”

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辱骂、亵渎、自我推销、误导、语无伦次或偏离主题的评论将被拒绝。

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