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Alive, Dead, and Hot: Schrödinger’s Cat Defies the Rules of Quantum Physics
Scitech Daily ^ | April 04, 2025 | University of Innsbruck

Posted on 04/04/2025 6:53:04 PM PDT by Red Badger

Quantum scientists have shown it’s possible to generate Schrödinger cat states in warmer conditions, challenging the assumption that cold is essential for quantum effects. Credit: SciTechDaily.com

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Researchers have pulled off a quantum feat that defies traditional expectations—they’ve created Schrödinger cat states not from ultra-cold ground states, but from warm, thermally excited ones.

Using a superconducting qubit setup, the team demonstrated that quantum superpositions can exist even at higher temperatures, overturning the long-held belief that heat destroys quantum effects. This breakthrough not only validates Schrödinger’s original “hot cat” concept but also paves the way for more practical and accessible quantum technologies.

Schrödinger’s Cat and Hot Quantum States

Schrödinger cat states are a remarkable feature of quantum physics, where a quantum system can exist in two opposing states at once. The concept comes from Erwin Schrödinger’s famous thought experiment, in which a cat is imagined to be both alive and dead simultaneously. In real-world experiments, similar quantum superpositions have been observed—not with actual cats, but in things like the positions of atoms and molecules, or the vibrations of electromagnetic resonators.

Until now, these kinds of superpositions were typically created by first cooling the quantum system to its ground state, its lowest possible energy level. But in a new breakthrough, researchers led by Gerhard Kirchmair and Oriol Romero-Isart have shown it’s possible to create Schrödinger cat states even when the system starts out thermally excited, or “hot.”

“Schrödinger also assumed a living, i.e. ‘hot’ cat in his thought experiment,” remarks Gerhard Kirchmair from the Department of Experimental Physics at the University of Innsbruck and the Institute of Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences (ÖAW). “We wanted to know whether these quantum effects can also be generated if we don’t start from the ‘cold’ ground state,” says Kirchmair.

In Erwin Schrödinger’s thought experiment, it is a cat that is alive and dead at the same time. Credit: University of Innsbruck/Harald Ritsch

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Creating Quantum Superpositions at Higher Temperatures

In their study, published today (April 4) in Science Advances, the team used a transmon qubit inside a microwave resonator to create the cat states. Remarkably, they succeeded at temperatures up to 1.8 Kelvin, around 60 times hotter than the resonator’s usual environment.

“Our results show that it is possible to generate highly mixed quantum states with distinct quantum properties,” explains Ian Yang, who performed the experiments reported in the study.

Adapting Protocols to Generate Hot Cat States

The researchers used two special protocols to create the hot Schrödinger cat states. These protocols were previously used to produce cat states starting from the ground state of the system. “It turned out that adapted protocols also work at higher temperatures, generating distinct quantum interferences,” says Oriol Romero-Isart, until recently Professor of Theoretical Physics at the University of Innsbruck and research group leader at IQOQI Innsbruck and since 2024 Director of ICFO – the Institute of Photonic Sciences in Barcelona.

“This opens up new opportunities for the creation and use of quantum superpositions, for example in nanomechanical oscillators, for which achieving the ground state can be technically challenging.”

Researchers generated highly mixed quantum states with distinct quantum properties. Credit: IQQOI Innsbruck

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Defying Expectations About Temperature and Quantum Interference

“Many of our colleagues were surprised when we first told them about our results, because we usually think of temperature as something that destroys quantum effects,” adds Thomas Agrenius, who helped develop the theoretical understanding of the experiment. “Our measurements confirm that quantum interference can persist even at high temperature.”

Implications for Future Quantum Technologies

These research findings could benefit the development of quantum technologies. “Our work reveals that it is possible to observe and use quantum phenomena even in less ideal, warmer environments,” emphasizes Gerhard Kirchmair. “If we can create the necessary interactions in a system, the temperature ultimately doesn’t matter.”

Reference:

“Hot Schrödinger Cat States”

by Ian Yang, Thomas Agrenius, Vasilisa Usova, Oriol Romero-Isart, Gerhard Kirchmair, 4 April 2025, Science Advances.

DOI: 10.1126/sciadv.adr4492

The study was funded by the Austrian Research Fund FWF and the European Union, among others.


TOPICS: Computers/Internet; Science; Weird Stuff
KEYWORDS: alive; cat; dead; hot; physics; quantummechanics; schrdinger; schrodingerscathouse; stringtheory
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To: Red Badger

Schroedinger’s cat, the best explanation for why Quantum computers are the best way to generate Fuzzy logic.


21 posted on 04/05/2025 5:01:30 AM PDT by dangus
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To: Red Badger

Alive and dead are mutually exclusive. Like yes and no, 0 and 1, true and false, male and female. If it’s one, it’s not the other. Saying “it can be both at the same time” doesn’t make it true.


22 posted on 04/05/2025 5:52:30 AM PDT by I want the USA back (America is once again GREAT!)
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To: I want the USA back

That’s in the normal, physical world.

The Quantum World is totally different..............


23 posted on 04/05/2025 5:54:19 AM PDT by Red Badger (Homeless veterans camp in the streets while illegals are put up in 5 Star hotels....................)
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To: Jamestown1630

In physics it is said some particles exhibits characteristics of both wave and a particle, but no proof has been shown they are both. It could easily just be our measurements are not proper to the situation or that what we call a wave or a particle is not a correct conclusion. Physics is very liquid in that sense; everything is subject to change.


24 posted on 04/05/2025 6:06:48 AM PDT by CodeToad ( )
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To: Red Badger
Quantum physics has always been waaay over my head. Does this have any practical application, or is it just a mind excercise?

Newton’s Three Laws of Motion are about as far as my brain will go…

25 posted on 04/05/2025 6:07:36 AM PDT by telescope115 (I NEED MY SPACE!!! 🔭)
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To: telescope115

The research goal is perfecting a “QUANTUM COMPUTER” that would be so powerful it can solve the most intricate problems in a flash, not being tied down to just two states.

Supposedly, a Quantum Computer can test ALL variables simultaneously and solve problems that a binary computer would take centuries.

What worries me is the eventual coupling of a perfected Quantum Computer and Artificial Intelligence.

A machine that ‘knows all and sees all”........IOW, a god..........


26 posted on 04/05/2025 6:13:45 AM PDT by Red Badger (Homeless veterans camp in the streets while illegals are put up in 5 Star hotels....................)
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To: telescope115
Newton’s Three Laws of Motion are about as far as my brain will go…

The "Three Body Problem" is one example of what a Quantum Computer could do..............

27 posted on 04/05/2025 6:18:02 AM PDT by Red Badger (Homeless veterans camp in the streets while illegals are put up in 5 Star hotels....................)
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To: Red Badger
Thanks for the explanation.

AI concerns me, too. My biggest fear is that we’ll create a “Frankenstein’s Monster” that we will lose control of. We have proven that, over a period of time, we can (as a species) make very irresponsible decisions that can turn around and bite us.

It’s our nature.

28 posted on 04/05/2025 6:24:11 AM PDT by telescope115 (I NEED MY SPACE!!! 🔭)
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To: telescope115

Colossus: The Forbin Project (originally released as The Forbin Project)..... 1970

https://en.wikipedia.org/wiki/Colossus:_The_Forbin_Project


29 posted on 04/05/2025 6:26:18 AM PDT by Red Badger (Homeless veterans camp in the streets while illegals are put up in 5 Star hotels....................)
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To: Red Badger

Yeah! There are others; The Terminator series, I, Robot, War Games….


30 posted on 04/05/2025 9:23:18 AM PDT by telescope115 (I NEED MY SPACE!!! 🔭)
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To: I want the USA back

“Alive and dead are mutually exclusive.”

It’s been explained to me that the primary condition of quantum superposition is uncertainty. The example presented is that of a coin flipped in the air, where the coin is both heads and tails.

There, I’ve just exhausted my total knowledge of quantum physics.


31 posted on 04/05/2025 2:53:34 PM PDT by sergeantdave (AI training involves stealing content from creators and not paying them a penny)
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