quantum entanglement is the bonding of two particles or objects even when they are very far apart – their respective properties are linked in a way that is not possible under the classical laws of physics.
It is a strange phenomenon that Einstein described as “remote spooky action“, but it’s its quirkiness that makes it so fascinating to scientists. 2021 studiesquantum confusion directly observed and recorded at the macroscopic scale – much larger than the subatomic particles normally associated with entanglement.
The dimensions involved are still very small from our point of view – the experiments involved two tiny aluminum drums one-fifth the width of a human hair – but they are certainly huge in the field of quantum physics.
“If you analyze the position and momentum data for the two drums independently, each will look hot,” said physicist John Teufelfrom the National Institute of Standards and Technology (NIST) in the USA last year.
“But when we look at them together, we can see that what appears to be the random movement of one drum is highly correlated with another, in a way only that is possible. quantum entanglement“
While there is nothing to say that quantum entanglement cannot happen with macroscopic objects, it was previously thought that the effects were not noticed at larger scales, or that perhaps the macroscopic scale was governed by some other set of rules.
Recent research shows that this is not the case. In fact, the same quantum rules apply here and can be seen in reality. Using microwave photons, the researchers vibrated the tiny drum membranes and kept them in a synchronized state in terms of their position and velocity.
To avoid tampering, a common problem with quantum states, the barrels were cooled, circulated, and measured in separate stages while in a cryogenically cooled enclosure. The states of the drums are then encoded in a reflected microwave field that works similarly to radar.
Previous studies had also reported macroscopic quantum entanglement, but the 2021 research went further: All necessary measurements were recorded rather than inferred, and the entanglement was generated in a deterministic, nonrandom way.
Inside series of related but separate experimentsWorking with macroscopic drums (or oscillators) in the case of quantum entanglement, researchers have demonstrated how it is possible to simultaneously measure the position and momentum of two drum heads.
“In our study, the drum heads exhibit a collective quantum movement,” said physicist Laure Mercier de Lepinayfrom Aalto University in Finland. “The battalions vibrate in opposite phase to each other, such that one is in the final position of the vibrational cycle and the other is in the opposite position at the same time.”
“In this case, the quantum uncertainty of the drums’ motion cancels out if the two drums are treated as one quantum-mechanical entity.”
The thing that makes this headline news is that it sticks around. Heisenberg’s Uncertainty Principle – the idea that position and momentum cannot be measured exactly at the same time. The principle states that recording any of the measurements will preclude the other through a process called quantum reverse action.
In addition to supporting other work showing macroscopic quantum entanglement, this particular piece of research uses this entanglement to avoid quantum backward action—mainly exploring the line between classical physics (where the Uncertainty Principle applies) and quantum physics (where it no longer applies). not visible).
One of the potential future applications of both sets of findings is quantum networks, being able to manipulate and entanglement objects on a macroscopic scale so that they can power next-generation communication networks.
“Besides practical applications, these experiments address how far macroscopic realm experiments can distinctly take the observation of quantum phenomena,” said physicists Hoi-Kwan Lau and Aashish Clerk, who were not involved in the studies. a comment on research published at the time.
Both of them first and second study published Science.
A version of this article was originally published in May 2021.
