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Thursday, June 08, 2023

Schrödinger’s cat makes better qubits

ECOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE

Schrödinger’s cat code — IMAGE: AN ILLUSTRATION OF SCHRÖDINGER’S CAT CODE view more
CREDIT: VINCENZO SAVONA (EPFL)

Quantum computing uses the principles of quantum mechanics to encode and elaborate data, meaning that it could one day solve computational problems that are intractable with current computers. While the latter work with bits, which represent either a 0 or a 1, quantum computers use quantum bits, or qubits – the fundamental units of quantum information.

“With applications ranging from drug discovery to optimization and simulations of complex biological systems and materials, quantum computing has the potential to reshape vast areas of science, industry, and society,” says Professor Vincenzo Savona, director of the Center for Quantum Science and Engineering at EPFL.

Unlike classical bits, qubits can exist in a “superposition” of both 0 and 1 states at the same time. This allows quantum computers to explore multiple solutions simultaneously, which could make them significantly faster in certain computational tasks. However, quantum systems are delicate and susceptible to errors caused by interactions with their environment.

“Developing strategies to either protect or qubits from this or to detect and correct errors once they have occurred is crucial for enabling the development of large-scale, fault-tolerant quantum computers,” says Savona. Together with EPFL physicists Luca Gravina, and Fabrizio Minganti, they have made a significant breakthrough by proposing a “critical Schrödinger cat code” for advanced resilience to errors. The study introduces a novel encoding scheme that could revolutionize the reliability of quantum computers.

What is a “critical Schrödinger cat code”?

In 1935, physicist Erwin Schrödinger proposed a thought experiment as a critique of the prevailing understanding of quantum mechanics at the time – the Copenhagen interpretation. In Schrödinger’s experiment, a cat is placed in a sealed box with a flask of poison and a radioactive source. If a single atom of the radioactive source decays, the radioactivity is detected by a Geiger counter, which then shatters the flask. The poison is released, killing the cat.

According to the Copenhagen view of quantum mechanics, if the atom is initially in superposition, the cat will inherit the same state and find itself in a superposition of alive and dead. “This state represents exactly the notion of a quantum bit, realized at the macroscopic scale,” says Savona.

In past years, scientists have drawn inspiration by Schrödinger’s cat to build an encoding technique called “Schrödinger’s cat code”. Here, the 0 and 1 states of the qubit are encoded onto two opposite phases of an oscillating electromagnetic field in a resonant cavity, similarly to the dead or alive states of the cat.

“Schrödinger cat codes have been realized in the past using two distinct approaches,” explains Savona. “One leverages anharmonic effects in the cavity, the other relying on carefully engineered cavity losses. In our work, we bridged the two by operating in an intermediate regime, combining the best of both worlds. Although previously believed to be unfruitful, this hybrid regime results in enhanced error suppression capabilities.” The core idea is to operate close to the critical point of a phase transition, which is what the ‘critical’ part of the critical cat code refers to.

The critical cat code has an additional advantage: it exhibits exceptional resistance to errors that result from random frequency shifts, which often pose significant challenges to operations involving multiple qubits. This solves a major problem and paves the way to the realization of devices with several mutually interacting qubits – the minimal requirement for building a quantum computer.

“We are taming the quantum cat,” says Savona. “By operating in a hybrid regime, we have developed a system that surpasses its predecessors, which represents a significant leap forward for cat qubits and quantum computing as a whole. The study is a milestone on the road towards building better quantum computers, and showcases EPFL’s dedication in advancing the field of quantum science and unlocking the true potential of quantum technologies.

Reference

Luca Gravina, Fabrizio Minganti, Vincenzo Savona. A critical Schrödinger cat qubit. Physical Review X Quantum 4, 020337. 07 June 2023. DOI: 10.1103/PRXQuantum.4.020337

JOURNAL

PRX Quantum

DOI

10.1103/PRXQuantum.4.020337

ARTICLE TITLE

Critical Schrödinger Cat Qubit

ARTICLE PUBLICATION DATE

7-Jun-2023

Wednesday, January 15, 2025

SCHRODINGERS CAT

This metaphorical cat is both dead and alive – and it will help quantum engineers detect computing errors

University of New South Wales

Cat on sofa — image:
This metaphorical cat has seven lives.
view more
Credit: UNSW Sydney

UNSW engineers have demonstrated a well-known quantum thought experiment in the real world. Their findings deliver a new and more robust way to perform quantum computations – and they have important implications for error correction, one of the biggest obstacles standing between them and a working quantum computer.

Quantum mechanics has puzzled scientists and philosophers for more than a century. One of the most famous quantum thought experiments is that of the “Schrödinger’s cat” – a cat whose life or death depends on the decay of a radioactive atom.

According to quantum mechanics, unless the atom is directly observed, it must be considered to be in a superposition – that is, being in multiple states at the same time – of decayed and not decayed. This leads to the troubling conclusion that the cat is in a superposition of dead and alive.

“No one has ever seen an actual cat in a state of being both dead and alive at the same time, but people use the Schrödinger’s cat metaphor to describe a superposition of quantum states that differ by a large amount,” says UNSW Professor Andrea Morello, leader of the team that conducted the research, published recently in the journal Nature Physics.

Atomic cat

For this research paper, Prof. Morello’s team used an atom of antimony, which is much more complex than standard ‘qubits’, or quantum building blocks.

“In our work, the ‘cat’ is an atom of antimony,” says Xi Yu, lead author of the paper.

“Antimony is a heavy atom, which possesses a large nuclear spin, meaning a large magnetic dipole. The spin of antimony can take eight different directions, instead of just two. This may not seem much, but in fact it completely changes the behaviour of the system. A superposition of the antimony spin pointing in opposite directions is not just a superposition of ‘up’ and ‘down’, because there are multiple quantum states separating the two branches of the superposition.”

This has profound consequences for scientists working on building a quantum computer using the nuclear spin of an atom as the basic building block.

“Normally, people use a quantum bit, or ‘qubit’ – an object described by only two quantum states – as the basic unit of quantum information,” says co-author Benjamin Wilhelm.

“If the qubit is a spin, we can call ‘spin down’ the ‘0’ state, and ‘spin up’ the ‘1’ state. But if the direction of the spin suddenly changes, we have immediately a logical error: 0 turns to 1 or vice versa, in just one go. This is why quantum information is so fragile.”

But in the antimony atom that has eight different spin directions, if the ‘0’ is encoded as a ‘dead cat’, and the ‘1’ as an ‘alive cat’, a single error is not enough to scramble the quantum code.

“As the proverb goes, a cat has nine lives. One little scratch is not enough to kill it. Our metaphorical ‘cat’ has seven lives: it would take seven consecutive errors to turn the ‘0’ into a ‘1’! This is the sense in which the superposition of antimony spin states in opposite directions is ‘macroscopic’ – because it’s happening on a larger scale, and realises a Schrödinger cat,” explains Yu.

Scalable technology

The antimony cat is embedded inside a silicon quantum chip, similar to the ones we have in our computers and mobile phones, but adapted to give access to the quantum state of a single atom. The chip was fabricated by UNSW’s Dr Danielle Holmes, while the atom of antimony was inserted in the chip by colleagues at the University of Melbourne.

“By hosting the atomic ‘Schrödinger cat’ inside a silicon chip, we gain an exquisite control over its quantum state – or, if you wish, over its life and death,” says Dr Holmes.

“Moreover, hosting the ‘cat’ in silicon means that, in the long term, this technology can be scaled up using similar methods as those we already adopt to build the computer chips we have today.”

The significance of this breakthrough is that it opens the door to a new way to perform quantum computations. The information is still encoded in binary code, ‘0’ or ‘1’, but there is more ‘room for error’ between the logical codes.

“A single, or even a few errors, do not immediately scramble the information,” Prof. Morello says.

“If an error occurs, we detect it straight away, and we can correct it before further errors accumulate. To continue the ‘Schrödinger cat’ metaphor, it’s as if we saw our cat coming home with a big scratch on his face. He’s far from dead, but we know that he got into a fight; we can go and find who caused the fight, before it happens again and our cat gets further injuries.”

The demonstration of quantum error detection and correction – a ‘Holy Grail’ in quantum computing – is the next milestone that the team will address.

The work was the result of a vast international collaboration. Several authors from UNSW Sydney, plus colleagues at the University of Melbourne, fabricated and operated the quantum devices. Theory collaborators in the USA, at Sandia National Laboratories and NASA Ames, and Canada, at the University of Calgary, provided precious ideas on how to create the cat, and how to assess its complicated quantum state.

“This work is a wonderful example of open-borders collaboration between world-leading teams with complementary expertise,” says Prof. Morello.

ENDS

This explainer video is available for media to embed in their stories.

Left to right: UNSW researchers Benjamin Wilhelm, Xi Yu, Prof Andrea Morello, Dr Danielle Holmes

Credit

UNSW Sydney

Journal

Nature Physics

DOI

10.1038/s41567-024-02745-0

Article Publication Date

14-Jan-2025

Wednesday, November 12, 2025

The Quantum Cat: A Campaign For Science And The Culture Of Reason – OpEd

November 12, 2025
By K.M. Seethi

Image: From the author’s file

As the world’s technological frontiers race ahead of our collective understanding, science today stands both indispensable and contested. The twenty-first century has brought incredible progress in quantum computing, genetic engineering, and artificial intelligence, even as it has witnessed a resurgence of pseudoscience, denialism, and the ideological distortion of knowledge. The real challenge before modern societies is not simply to multiply discoveries, but to safeguard the very spirit of inquiry that makes discovery possibl

In the first week of November 2025, as the United Nations marks the International Year of Quantum Science and Technology (IYQ 2025), the South Indian state of Kerala has added its own creative turn to the celebration. The Centre for Science in Society (C-SiS) at the Cochin University of Science and Technology (CUSAT) in collaboration with the Kerala Sastra Sahitya Parishad (KSSP) has launched the Quantum Cat campaign — a science exhibition and outreach movement that travels across ten districts. The exhibition opened on November 7 at CUSAT and will run through December, bringing to schools, colleges, and communities an experience of the “quantum century.”

But this is not just another science event. It gets underway at a critical moment when anti-science attitudes and pseudoscientific beliefs are gaining ground, encouraged by a political climate that seeks to rewrite knowledge through ideology. The Sangh Parivar’s attempts to dilute and distort scientific theories in curricula and promote mythical claims at official science events reflect a major crisis — the erosion of scientific temper, a constitutional duty that India once proudly upheld. Against this background, the campaign acquires crucial social meaning – it defends reason itself.

KSSP President Meera Bhai told this author that the initiative “seeks to promote science and scientific inquiry from the school level onwards,” continuing a long tradition that began with the Parishad’s legendary Halley’s Comet campaign in 1986. Then, too, KSSP fought superstition by turning fear into curiosity. Today, as irrationality resurfaces in new forms, such as astrology apps, miracle cures, WhatsApp “Vedic science,” the Quantum Cat becomes a new mascot of rational inquiry. Recent findings from Kerala Padanangal 2.0, KSSP’s statewide social survey, show that one in three people in Kerala still depend on astrology to make life decisions — a surprising figure in a state known for high literacy and human development. This coexistence of reason and belief, science and superstition, is precisely the paradox the campaign seeks to address.

The Century of Quantum Science

The International Year of Quantum Science and Technology commemorates a hundred years since the birth of quantum theory, the most successful and puzzling scientific framework ever devised. When Max Planck proposed in 1900 that energy comes in discrete “quanta,” he began a revolution. Einstein used that idea to explain light as particles, Bohr built his model of the atom, Heisenberg introduced the uncertainty principle, and Schrödinger described matter as waves. Together they showed that at the subatomic level, nature defies common sense. In the quantum world, particles exist in multiple states at once — a phenomenon called superposition — and remain mysteriously connected across vast distances through entanglement. Observation itself determines outcomes, making the observer part of reality. This radical idea — that measurement changes what is measured — has transformed every field of science.

Today, quantum principles underlie technologies that define modern life, from lasers, semiconductors, to solar cells, and GPS. They are now driving quantum computing and quantum communication, promising faster problem-solving and unbreakable data security. In chemistry and biology, quantum mechanics explains the structure of molecules, the efficiency of photosynthesis, and even how birds sense magnetic fields.

For some scientists, quantum mechanics defies classical explanation, operating in a realm where causality is uncertain and probability replaces determinism. Physicist Babu Joseph, former Vice-Chancellor of CUSAT, explains it more precisely: “The Schrödinger’s Cat captures the essence of quantum mechanics, which asserts that there is no observer-independent reality. The standard binary — exist or not — isn’t true. There can be combinations of varying degrees of possibilities until the observer interacts with the system.” That insight lies at the heart of the superposition principle, the backbone of quantum mechanics, he told this author.

Quantum science thus transforms how we see both matter and meaning. It teaches that reality is not fixed but relational, not given but discovered through interaction — a lesson as relevant to society as to physics.

The Cat in the Box: From Paradox to Possibility

Erwin Schrödinger’s famous cat was never real. Conceived in 1935, it was a thought experiment to expose the absurd implications of early quantum theory. In Schrödinger’s imaginary box, a cat’s life depends on a random atomic event. Until someone opens the box, the cat is both alive and dead — a paradox meant to question how far quantum laws can extend into the visible world.

Modern physics resolves the puzzle through decoherence: real cats interact with their environment, collapsing the ambiguity long before observation. However, the Quantum Cat survived in imagination, literature, and popular science — precisely because it dramatises the central mystery of observation and reality. It asks a timeless question: Can we know the world without changing it? For KSSP’s campaigners, this cat is a metaphor for scientific curiosity. It provokes questions — How can something be alive and dead at once? What does observation mean? — and in doing so, it invites thinking, reasoning, and dialogue.

The cat also teaches humility. It reminds us that nature does not always obey our common sense, and that our perceptions are limited. In a society where superstition often pretends as wisdom, such humility is a moral necessity. As Meera Bhai noted, “KSSP’s science campaigns have always connected wonder with reason — from Halley’s Comet to the Quantum Cat — to make people see the beauty of questioning.”

Used symbolically, Schrödinger’s cat bridges imagination and logic. It tells students that science is not dry or distant but full of wonder and paradox. It shows that curiosity and creativity belong together. And in public life, it becomes a counter-symbol — against fatalism, dogma, and blind belief.

The Quantum Imagination

Over the past century, quantum ideas have travelled far beyond the laboratory, shaping the way philosophers and social scientists think about knowledge, perception, and reality. Just as a quantum particle can exist in many states until observed, societies too can contain multiple, often contradictory realities — rational and irrational, secular and superstitious, progressive and reactionary — coexisting beneath the surface. These contradictions persist until some event, such as an election, a protest, or a crisis, forces them into view and “collapses” them into a single, visible outcome.

In this sense, Schrödinger’s Cat has become more than a symbol of physics; it is a metaphor for social life itself. People may believe in science yet rely on superstition, or support equality while practising exclusion. Sociologists have long explored such tensions. Émile Durkheim described societies as combining both mechanical and organic solidarity; Georg Simmel’s “stranger” is simultaneously near and distant; Karl Marx’s theory of alienation shows workers as both creative and estranged. These examples illustrate that ambiguity and coexistence, not clarity and uniformity, often define modern life.

Thus, quantum metaphors remind us that uncertainty is not the absence of understanding but a sign of complexity — and that observation itself, whether in science or society, changes what is observed. To recognise this is to accept responsibility: the act of looking, questioning, and interpreting is also an act of participation. In this sense, the observer effect is not limited to physics. Every social study, every public debate, every act of journalism alters what it observes. Recognising this responsibility — the role of agency — is a vital part of both scientific and civic inquiry. The Quantum Cat, seen in this light, becomes a symbol of reflective citizenship: one that questions, observes, and acts, knowing that observation affects reality.

The link between science and society defines KSSP’s legacy. Founded in 1962, it has grown beyond a science club into a people’s science movement connecting empirical reasoning with social progress. Its campaigns on environment, energy, health, and education have always sought to make knowledge democratic and life-oriented. The Quantum Cat campaign continues this mission, using a global scientific breakthrough to renew Kerala’s commitment to rational thought. From Halley’s Comet to Quantum Cat, the message remains the same – science belongs to the people. In 1986, KSSP volunteers explained that comets were celestial bodies, not omens, and forty years later, they travel again, showing that the cat is a metaphor for observation and reason. The persistence of astrology and pseudo-science reveals that education alone cannot ensure enlightenment. What is needed, as KSSP calls vijnanabodh, is the consciousness of science as a way of life—anchored in curiosity, scepticism, and empathy.

Toward a Culture of Reason

The Quantum Cat campaign, therefore, is not just a celebration of physics. It is a cultural intervention, telling that science and democracy share the same foundation – reasoned freedom. In an era when faith is marketed as fact and propaganda as knowledge, the defence of reason becomes a moral act.

Quantum theory offers a powerful metaphor for today’s struggle between reason and unreason. It shows that reality is not binary but a field of probabilities influenced by interaction, just as social progress depends on participation, dialogue, and openness. The spirit of quantum thought underlines democratic inquiry. In this sense, KSSP’s Quantum Cat invites young minds to look into the “box” of their own world, to question, observe, and think freely. It tells us that curiosity is not disobedience, doubt is not weakness, and imagination is part of knowledge.

As Babu Joseph says, “The Newtonian cat is either dead or alive; the quantum cat is both—until you look.” So too with society, it holds both reason and prejudice until we choose which to see. The campaign restores science’s humane meaning, not as apparatus but as a way of knowing that dignifies life and keeps curiosity alive amid ideological darkness.

K.M. Seethi

K.M. Seethi is is Director, Inter University Centre for Social Science Research and Extension (IUCSSRE), Mahatma Gandhi University (MGU), Kerala. He also served as ICSSR Senior Fellow, Senior Professor of International Relations and Dean of Social Sciences at MGU. One of his latest works is "ENDURING DILEMMA Flashpoints in Kashmir and India-Pakistan Relations."

Monday, May 01, 2023

Physicists Set New Quantum Record With Heaviest 'Schrödinger Cat' Yet

Story by Mike McRae • Yesterday - ScienceAlert

Intense Grey Cat In Box

Atiny vibrating crystal weighing little more than a grain of sand has become the heaviest object ever to be recorded in a superposition of locations.

Physicists at the Swiss Federal Institute of Technology (ETH) Zurich coupled a mechanical resonator to a type of superconducting circuit commonly used in quantum computing to effectively replicate Erwin Schrödinger's famous thought experiment on an unprecedented scale.

Ironically, Schrödinger would be somewhat skeptical that anything so large – well, anything at all – could exist in a nebulous state of reality.

Superposition states have no equivalent in our everyday experience. Watch a football drop, and you can track its rate of fall with a stopwatch. Its final resting position is as clear as day, and even how it spins in flight is obvious.

Should you close your eyes as it falls, there's no reason to think these states of location or behavior might be any different. Yet in quantum physics, features like position, spin, and momentum don't exist in any meaningful way until you see the ball resting on the ground.

Along with that other heavyweight of theoretical physics, Albert Einstein, Schrödinger wasn't exactly keen on interpretations of experiments that suggested particles lacked precise properties until an observation gave them one.

To show just how absurd the whole idea was, the Nobel-Prize-winning Austrian described a scenario where a particle's unobserved position was linked to the life of an unobserved cat.

Imagine, if you will, a particle randomly spat from a decaying atom, striking a Geiger counter, causing a vial of poison to shatter, instantly killing a cat. Since this all occurs inside a box, the events and their timing remain unobserved.

Going by what's known as the Copenhagen Interpretation of quantum physics, the unseen system exists in a state of all possibilities until its final state is observed. The particle is both emitted and not-emitted. The Geiger counter is activated and not activated. The vial of poison is shattered and not shattered. And the cat is both alive and dead.

This mortal blur is virtually impossible to picture but is easily represented in the wave-like equation of Schrödinger's own devising.

Nearly a century on, Schrödinger's cat is no longer a joke. It's been observed not only in tiny particles but in entire molecules (not to mention in clusters of thousands of atoms). We can manipulate the box to ensure the cat never dies. We can even tinker with the setup to pull the cat apart. In fact, entire technologies are founded on the very principles of objects in states of superposition.

While no actual cats have ever been threatened by a quantum experiment – because, you know, ethics – the theory remains clear. Objects as large as cats, or indeed, humans, elephants, or even dinosaurs, can exist in states of superposition in the same way as electrons, quarks, and photons.

The mathematics leave little room for doubt, yet observing the effects of such a blurred existence on a large scale is a whole other story.

On the atomic level, a smear of unrealized fates can be seen using fairly rudimentary equipment. As the properties of objects grow, the fingerprints of superposition become harder to tease out experimentally.

In this latest experiment, a high-overtone bulk acoustic-wave resonator, or HBAR, served as a 16.2 microgram cat. What it lacked in whiskers and fish breath, it made up for in the fact it could hum across a short range of frequencies when powered by a current.

"By putting the two oscillation states of the crystal in a superposition, we have effectively created a Schrödinger cat weighing 16 micrograms," says senior author and ETH Zurich physicist Yiwen Chu.

For the roles of a radioactive atom, Geiger counter, and poison, the team used a transmon, a superconducting circuit that served as the experiment's power source, sensor, and superposition.

Hooking the two together allowed the researchers to set the HBAR into motion so that its oscillations quivered in two phases at once, a phenomenon that fed back into the transmon.

Just how big future experiments could go is an open question. On a practical front, pushing the limits of scale on superposition could lead to new methods for making quantum technology more robust or form the basis of ever-more sensitive tools for studying matter and the cosmos.

Fundamentally, there are still questions on what it means for matter to be in a superposition at all. Despite decades of advancement in making quantum mechanics more precise, there is still no clarity on why opening the box should make any difference to the fate of Schrödinger's cat.

Just what it means to turn a maybe into an actuality remains as much a mystery in particle physics as when Schrödinger dreamed up his preposterous idea of a cat that should not be.

This research was published in Science.

Saturday, April 05, 2025

Hot Schrödinger cat states created

University of Innsbruck

ADAM WEISHAUPT'S ALMA MATER

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

Quantum states can only be prepared and observed under highly controlled conditions. A research team from Innsbruck, Austria, has now succeeded in creating so-called hot Schrödinger cat states in a superconducting microwave resonator. The study, recently published in Science Advances, shows that quantum phenomena can also be observed and used in less perfect, warmer conditions.

Schrödinger cat states are a fascinating phenomenon in quantum physics in which a quantum object exists simultaneously in two different states. In Erwin Schrödinger's thought experiment, it is a cat that is alive and dead at the same time. In real experiments, such simultaneity has been seen in the locations of atoms and molecules and in the oscillations of electromagnetic resonators. Previously, these analogues to Schrödinger’s thought experiment were created by first cooling the quantum object to its ground state, the state with the lowest possible energy. Now, researchers led by Gerhard Kirchmair and Oriol Romero-Isart have demonstrated for the first time that it is indeed possible to create quantum superpositions from thermally excited states. “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 their study published in the Science Advances, the researchers used a transmon qubit in a microwave resonator to generate the cat states. They succeeded in creating the quantum superpositions at temperatures of up to 1.8 Kelvin – which is sixty times hotter than the ambient temperature in the cavity. “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.

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.”

“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”.

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.”

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

Publikation: Hot Schrödinger Cat States. Ian Yang, Thomas Agrenius, Vasilisa Usova, Oriol Romero-Isart, Gerhard Kirchmair. Science Advances 2025 DOI: 10.1126/sciadv.adr4492 [arXiv:2406.03389]

Researchers generated highly mixed quantum states with distinct quantum properties.