Einstein's 'Spooky Action': Bizarre Quantum Phenomenon Demonstrated on Massive Scale in World First

Quantum entanglement is a mind-boggling phenomenon in which pairs, or groups, of particles interact with each other in such a way that they defy the classical laws of physics. One object can seemingly influence another simultaneously, even if they have no direct physical connection and are separated by vast distances—such as the length of the universe.

Entanglement, which was once described by Albert Einstein as "spooky action at a distance," is a cornerstone of quantum mechanics—the bizarre physics of the very small—and plays an important role in potentially revolutionary technologies like quantum computers.

It is extremely difficult to produce artificially because the slightest environmental disturbances can break the connections between the particles in question, so thus far, it has only been demonstrated on a tiny scale using particles of light, or other similarly sized atomic objects.

However, in a new journal Nature study, an international team of scientists from the University of New South Wales, Australia, the University of Chicago and the universities of Jyväskylä and Aalto, both in Finland, have generated quantum entanglement on a massive scale, in a world first that promises to expand our understanding of quantum physics.

The team managed to entangle the motion of two aluminum drumheads on a silicon chip by applying microwaves to the circuit, which made them vibrate at high frequencies. These drumheads are tiny, measuring just 15 micrometers across—about the width of a human hair—but they contain many billions of atoms, which is massive for the quantum scale, and far larger than any object that has been entangled before.

"In our system, we have two very small vibrating drumheads," Aashish Clerk, a professor at the Institute for Molecular Engineering at the University of Chicago, told Newsweek. "If you just look at one of the drumheads, its motion would appear to be completely random. However, if you look at both, you would see that the motion of the two drumheads are extremely correlated: when one drumhead moves up, the other moves down, etc."

"This correlation is too strong to be understood using classical physics," he said. "This entanglement is something that Einstein always found problematic, hence his term 'spooky action at a distance.'"

The researchers had to eliminate all forms of environmental disturbances, so they conducted the experiment at temperatures close to absolute zero—minus 459.67 degrees Fahrenheit. Surprisingly, the researchers found that their approach led to states of entanglement which lasted for long periods of time, sometimes up to half an hour.

The new findings demonstrate that it is possible to generate exotic quantum states in relatively large objects, which could have a number of significant implications.

This is an illustration of the 15-micrometer-wide drumheads prepared on silicon chips used in the experiment. The drumheads vibrate at a high ultrasound frequency, and the peculiar quantum state predicted by Einstein was created from the vibrations. Aalto University/Petja Hyttinen & Olli Hanhirova, ARKH Architects.

"Entanglement is the key resource behind many potential technologies that harness the most counter-intuitive aspects of quantum mechanics; this includes quantum computers, and new kinds of extremely precise sensors," Clerk said.

"This research demonstrates that we now have the ability to generate and stabilize the motion of large objects in these unusual entangled states. Small vibrating objects already play a crucial role in a number of different applications—for example, as sensors and filters in your cell phone. Quantum versions of these mechanical devices could have a host of applications—for example, as a kind of 'bus' that could move quantum information from one kind of physical system to another," he said.

"More fundamentally, there are basic questions about whether one needs to modify the laws of quantum mechanics when describing large, macroscopic objects," he added. "Some believe that the poorly understood interplay of quantum mechanics and gravity requires this. These kinds of experiments that prepare large objects in truly quantum states are a promising route to being able to help answer these questions."