Physicists Claim They've Quantum Entangled a Tardigrade With a Qubit. But Have They?

 

(David Spears FRPS FRMS/Corbis Documentary/Getty Images)

A group of physicists claims to have linked a superconducting qubit and a tardigrade, bringing quantum physics' frigid, small, and well-controlled world into life's "hot and moist" systems.

However, many quantum researchers argue that the poor tardigrade was not entangled in a significant way, as stated in this preprint publication.

"I also don't know how serious the authors were about this — it may be a joke," comments Douglas Natelson, a physics professor at Rice University.

"It's worth noting, however, that the authors did not associate a tardigrade with a qubit in any meaningful way. This isn't a case of 'quantum biology.'"

When two or more particles are linked in such a way that a fundamental feature they share – such as position, momentum, or polarisation – is not independent of each other, this is known as quantum entanglement.

For example, if you found a right-handed glove in your drawer, you might be sure the lost glove would fit your left hand: knowing anything about one tells you something vital about the other, and that information is not random.

Entanglement occurs in quantum systems naturally when particles collide or interact in almost any other way. Although Albert Einstein was not a fan, scientists have demonstrated that entanglement is not difficult to induce in the years following.

Scientists have done a good job of tying together larger and larger objects. They've caught molecular ions, bigger nanoparticles, and even teeny-tiny diamonds in their web.

All of such systems, however, are still very small, usually very cold, and well-organized. A tardigrade, on the other hand, is a fairly big collection of frozen, messy biological material, even in its dried, 'indestructible' state.

The researchers used a tardigrade species named Ramazzottius varieornatus and placed it in a dehydrated cryptobiosis in their new preprint publication published on arXiv. They then chilled it to only 10 degrees Celsius above absolute zero and placed it under 0.000006 millibars of pressure.

The scientists next conducted experiments in which they attempted to entangle the tardigrade with two superconducting transmon qubits, discovering that the critter and the qubits "observed coupling."

They heated up the tardigrade after roughly 420 hours of experimentation, and it went on its merry way.

Following some early dramatic headlines, however, a number of physicists and science writers are pointing out that this isn't genuinely entanglement - or at least not something new.

OnTwitter, physicist and science journalist Ben Brubaker says, "The qubit is an electrical circuit, and putting the tardigrade next to it changes it through the rules of electromagnetism we've known about for more than 150 years."

"A speck of dust adjacent to the qubit would have a similar effect," says the researcher.

So, in a quantum sense, this isn't actually an entangled tardigrade at all. In actuality, depending on whose physicist you ask, it's either a classical (non-quantum) interaction between a qubit and a tardigrade, or there's no evidence of interaction at all, and they just placed a very cold, very low-pressure tardigrade on a qubit.

The authors of the new study do acknowledge that this is a new record "for the conditions under which a complex form of life might exist," which is perhaps the most intriguing aspect of the new research. We'll have to wait for peer review to verify if these assertions are true.

As fascinating as the thought of a quantum tardigrade may sound, we don't appear to have enough evidence for the first living organism to have been quantum entangled at this time.

We also don't know how seriously we should take this research, or whether the researchers were aware that their work would be scrutinised as severely as it has been.

Tara Roberson, a researcher at the Australian Research Council Centre of Excellence for Engineered Quantum Systems who focuses in science communication and 'hype,' says, "I did question about the timing of this preprint being published and given out to the wider public."

"In general, you don't put something sophisticated and thick – academically hard – up in December if you want it to be read. However, if you're uploading something funny and simple for audiences, now is the moment!"

"I'm not sure if it was part of the research team's thinking, but the idea of an entangled tardigrade certainly made me laugh."

The Research is Originally Published at arXiv.