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Science

New Work Achieves a Pure Quantum State Without the Need For Cooling (phys.org) 40

alternative_right shares a report from Phys.org: Three nano-glass spheres cling to one another. They form a tower-like cluster, similar to when you pile three scoops of ice cream on top of one another -- only much smaller. The diameter of the nano cluster is ten times smaller than that of a human hair. With the help of an optical device and laser beams, researchers at ETH Zurich have succeeded in keeping such objects almost completely motionless in levitation. This is significant when it comes to the future development of quantum sensors, which, together with quantum computers, constitute the most promising applications of quantum research.

As part of their levitation experiment, the researchers, led by adjunct professor of photonics Martin Frimmer, were able to eliminate the gravitational force acting on the glass spheres. However, the elongated nano object still trembled, similar to how the needle on a compass moves when settling into position. In the case of the nano cluster, the trembling motion was very fast but weak: the object made around one million deflections per second, each measuring only a few thousandths of a degree. This tiny rotational oscillation is a fundamental quantum motion exhibited by all objects, which physicists call zero-point fluctuation.

To date, no one has been successful in detecting these tiny movements for an object of this size as precisely as the ETH researchers have now done. They achieved this because they were able to largely eliminate all motions that originate from the field of classical physics and obscure the observation of quantum movements. The ETH researchers attribute 92% of the cluster's movements in their experiment to quantum physics and 8% to classical physics; they therefore refer to a high level of quantum purity. And the records do not stop there: The researchers accomplished all of this at room temperature. Quantum researchers usually have to cool their objects to a temperature close to absolute zero (-273 degrees Celsius) using special equipment. This was not required here.
The research has been published in the journal Nature Physics.

New Work Achieves a Pure Quantum State Without the Need For Cooling

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  • Now it's quantum states. Can you say vaporware ?
    • Now it's quantum states. Can you say vaporware ?

      This.

      The ETH researchers attribute 92% of the cluster's movements in their experiment to quantum physics and 8% to classical physics; they therefore refer to a high level of quantum purity.

      And if we find the researchers attributed their winnings wrongly, will they face a high level of scrutiny? Or will the funding just keep coming for silly work no matter what? Even the vaporware we never learned from didn’t have this kind of blind backing.

      • If true, it represents a new sensor, a new detector... As the article states: "The three quantum objects, stacked up in less than the width of a human hair", would be able to detect ?? I find this interesting because... sensors are almost magical to me. They are the interface between the computer and the sensory world we experience. From the article: " The development of sensors to measure tiny forces such as those of gas molecules or even elementary particles that act on the sensor is also conceiva
        • Re: (Score:3, Insightful)

          by geekmux ( 1040042 )

          If true, it represents a new sensor, a new detector... As the article states: "The three quantum objects, stacked up in less than the width of a human hair", would be able to detect ?? I find this interesting because... sensors are almost magical to me. They are the interface between the computer and the sensory world we experience. From the article: " The development of sensors to measure tiny forces such as those of gas molecules or even elementary particles that act on the sensor is also conceivable. This would be useful in the search for dark matter."........ I agree. It is in the baby stages for sure, but if I were them I would expose those little quantum babies to different forces, and molecules, and study what happens. a fundamental breakthrough... I sense (pun), is in the making here.

          Its rather ironic you used dark matter to justify continued support, since I was far more worried about the if-false-what happens rather than your If true scenario filled with a magical amount of optimism.

          Looking at ”dark matter” from a breakthrough point of view, it is still a term riddled with marketing bullshit created by a group of “experts” who don’t have a single fucking clue about the 95%+ of matter in the universe they study, but had to come up with a very cool name. W

      • ETH is more widely respected than you are.

        • ETH is more widely respected than you are.

          Fan-fucking-tastic. ETH is also made up of humans. Which makes them just as fallible as you or I.

          Within the realm of infinitely smaller micro-measuring of states, I’m just curious; what happened to margin of error? Is there a chance this breakthrough exists purely within the plus-minus range? 92% of taxpayers would like to know what happens to funding when the marketing proves more sound than science, because 100% of taxpayers know science has been found to lie for profit.

    • by JoshuaZ ( 1134087 ) on Thursday August 07, 2025 @08:21AM (#65572426) Homepage
      1) You seem to not understand how basic science works. No one is claiming this has some immediate application. 2) Superconductors have gotten much better over the last 40 years and are in fact being used all over. The oldest usage was in MRI machines which when they started were incredibly expensive, and are now cheap enough that there are even some in developing countries. Similarly, we now even have superconductors on parts of the regular electric grid. The first was the Holbrook project https://en.wikipedia.org/wiki/... [wikipedia.org] but there are others as well. So no, superconductors are not vaporware.
      • by Junta ( 36770 )

        I assume he meant the 'without cooling' part, where we got real excited for a minute there that room temp, normal pressure superconductiong had been cracked.

    • Vaporware? That's in the eye of the beholder's cat.

    • Now it's quantum states. Can you say vaporware?

      Sure, I can say “vaporware.” I just wouldn’t apply it to a published, peer-reviewed experiment with real-world measurements and downloadable data.

      Vaporware refers to a product that's marketed but never ships. This is fundamental research, not product development. What ETH Zurich demonstrated isn’t a vague promise—it’s a mechanical oscillator cooled to near its quantum ground state (state purity of 92% ) at room temperature, an achievement many thought required costly cryo

  • by Cley Faye ( 1123605 ) on Thursday August 07, 2025 @04:50AM (#65572148) Homepage
    Regardless of this accomplishment, whether it's real or not (I'm clearly now knowledgeable enough to make any claim on that), I wonder what does "motionless" mean. I usually think motion is always relative, so I assume these things weren't moving relative to the lab around them. But does it really count as motionless from a physics perspective?
    That's a genuine question. I suppose there's some basic for things to qualify as motionless, but when we're talking about these kind of scales, it feels like keeping up with a huge rock going through space isn't really motionless.
    • The motion here is a mix of two things, motion relative to the lab (caused by external forces) and internal motions from thermal effects (caused by the temperature of the spheres, essentially it's atoms jiggling back and forth). They used an optical trap to suppress both, essentially both cooling and levitating the spheres using lasers. The remaining motion is mostly due to quantum excitations, which is interesting, because those are hard to observe in objects bigger than a couple of atoms. Not immediately
    • Regardless of this accomplishment, whether it's real or not (I'm clearly now knowledgeable enough to make any claim on that), I wonder what does "motionless" mean. I usually think motion is always relative, so I assume these things weren't moving relative to the lab around them. But does it really count as motionless from a physics perspective?

      That's a genuine question. I suppose there's some basic for things to qualify as motionless, but when we're talking about these kind of scales, it feels like keeping up with a huge rock going through space isn't really motionless.

      You're right to be skeptical of the term "motionless" in physics, because motion is always relative. But in quantum mechanics, we are observing (read: measuring) states, not things, so there is more to motion than what fits into the Gallilean perspective on motion that you seem to be working from.

      The key idea here is Einstein's principle of equivalence, which tells us that there's no meaningful absolute frame of rest in the universe—just local frames where physics behaves the same whether you're at

  • by Viol8 ( 599362 ) on Thursday August 07, 2025 @04:59AM (#65572162) Homepage

    "were able to eliminate the gravitational force acting on the glass spheres."

    Umm, sorry? I assume they mean they negated it somehow unless they really have made a breakthrough in anti gravity physics!

    • by 93 Escort Wagon ( 326346 ) on Thursday August 07, 2025 @05:25AM (#65572196)

      No, they actually changed the gravitational constant!

      It was mainly the work of their new intern, Q Jr.

    • It seems they are simply saying that their levitation method acts on all the matter of the sphere uniformly, thereby countering gravity. When you get right down to it, a table is an anti-gravity device, isn't it? Not much to get enraged about here.

      • by Viol8 ( 599362 )

        "a table is an anti-gravity device, isn't it"

        No. Gravity is in full control of it and everything on it.

        • You seem unclear on the concept of equal and opposite.

          • by Viol8 ( 599362 )

            You seem unclear on the concept of anti gravity. Clue: It nullifies gravitys effect.

            • Oh, like a hot air balloon? Speaking of hot air, you should just shut up about physics and spare us all the agony.

              • by Viol8 ( 599362 )

                I wonder how people as stupid as you even manage to operate a web browser. So you seem unable to grasp the basic fundamental difference between resisting gravity and anti gravity which even children can understand.

                I'm afraid I can't be bothered to climb far enough down the evolutionary ladder to continue arguing with you but feel free to have the last word so I can have a good laugh later :)

  • by quax ( 19371 ) on Thursday August 07, 2025 @06:40AM (#65572302)

    Heat is Brownian motion. The news here is that this was accomplished with laser cooling rather than cryogenically.

    To quote from the abstract:

    Here we use coherent scattering into a Fabry-Perot cavity to cool the megahertz-frequency librational mode of an optically levitated silica nanoparticle from room temperature to its quantum ground state.

    This kind of cooling is much less energy intensive and opens up these kind of systems for further experiments and compact technological integration (hence the reference to sensors).

  • by gweihir ( 88907 ) on Thursday August 07, 2025 @11:20AM (#65572828)

    Quantum sensors are a promising field. Quantum computers have been crap, are crap and will remain crap. Apparently, today, the actual real world record for factorization with a QC is 35. Such impressive power!

    • by Tablizer ( 95088 )

      Quantum computers have been crap, are crap and will remain crap.

      Shhhh, we'll need a new bubble to rescue us when the AI market pops.

    • Every time this particular troll pollutes a technical discussion thread, the choreography is the same: they start with a safe, uncontroversial statement, pivot to a strawman caricature of the actual topic, then swing away at the cartoon version while ignoring the real details. It’s lazy, it’s predictable, and it’s exactly what’s on display here.

      Quantum sensors are a promising field.

      True. And this experiment — near-ground-state cooling of a mechanical oscillator at room temperature — is the kind of enabling re

  • by PPH ( 736903 )

    ... they balanced three balls. Let's see them do that while riding a unicycle and then I'll be impressed.

  • Their experiment did require cooling, and did not happen at "room temperature". It is just that they were able to limit the scope of what part of their experimental setup they needed to cool (to temperatures near 0K) to a very small part of the whole. Which may of course be a nice achievement, but it is not "without the need for cooling" or "at room temperature".
  • This is one of those papers that hits the trifecta: elegant physics, non-obvious engineering, and a mountain of reasons to be skeptical of the hype train.

    Researchers at ETH Zurich have successfully cooled a mechanical oscillator—specifically, the librational mode of an optically levitated nanoparticle—to its quantum ground state at room temperature. No dilution refrigerators, no liquid helium, just vacuum, lasers, and ruthless noise suppression. The result? A phonon occupation of 0.04 and quantu

... though his invention worked superbly -- his theory was a crock of sewage from beginning to end. -- Vernor Vinge, "The Peace War"

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