In his cult classic “Ender’s Game,” Orson Scott Card envisioned a world where Earth’s brightest and tragically youngest tacticians could command armies over vast distances instantaneously using a device called the ansible.
While the jury is still out on whether such a device will ever be possible, this week scientists at the US Department of Energy’s (DoE) Brookhaven National Laboratory detailed a “never-before-seen” type of quantum entanglement that they say , may one day enable powerful new communication tools and computers.
Scientists have been trying to exploit quantum entangled particles ever since the phenomenon was theorized in the early 20th century, and the topic has been hotly debated among physicists for decades. However, late last year, three scientists – Alain Aspect, John Clauser and Anton Zeilinger – were awarded the Nobel Prize in Physics for their work on quantum entanglement.
A “new” kind of quantum entanglement
Brookhaven’s latest discovery was made while exploring a new means of probing the inner workings of atomic nuclei. The experiments, described in the journal Science Advances, used Brookhaven’s Relativistic Heavy Ion Collider to accelerate particles to nearly the speed of light.
Usually, the collider would tear the gold particles apart. This would blur the lines between protons and neutrons and allow scientists to study quarks and gluons – two of the elementary particles that form the nucleus of atoms – in an environment similar to that of the early galaxy.
But instead of tearing them apart, the gold particles were surrounded by a cloud of photons and allowed to pass past each other.
According to Brookhaven, as they crossed paths, a series of quantum fluctuations caused by the interaction between photons and gluons produced a new particle that rapidly decayed into a pair of charged pions. When measured, these pions have allowed scientists to map the distributions of gluons within the nucleus of the atom.
In a blog post, Daniel Brandenburg, a STAR collaboration member who worked on the project, said the technique works a bit like a scan in a doctor’s office, but instead of seeing inside a patient’s brain, Scientists are peering into the inner workings of protons.
It was during these measurements that the scientists say they observed a curious phenomenon: a new type of quantum interference.
“We measure two outgoing particles and clearly their charges are different – they are different particles – but we see interference patterns which indicate that these particles are entangled or in sync with each other, even though they are distinguishable particles,” Zhangbu Xu , a Brookhaven National Labs physicist said in the blog post.
According to Brookhaven, most other observations of entanglement have been between identical photons or electrons. “This is the first experimental observation of entanglement between dissimilar particles,” says Brandenburg.
What are Russians looking for?
Brookhaven was one of three national DoE labs targeted by Russian hackers over the summer.
According to Reuters, between August and September, a group of cybercriminals known as Cold River used phishing emails and fabricated login pages to harvest employee credentials from Brookhaven, Argonne and Lawrence Livermore National Laboratories.
The facilities house a variety of nuclear research programs, including several related to the maintenance and development of US strategic stockpiles.
Although Reuters was able to confirm Cold River’s involvement with the help of five cybersecurity experts using fingerprints associated with the group, it was unable to determine whether the hackers were capable of breaching the DoE’s defenses .
Cold River has had previous successes compromising high-profile targets. One of the group’s most recent targets was Richard Dearlove, the former head of Britain’s foreign intelligence service MI6, whose emails were leaked in May.
A prelude to the quantum internet
DoE’s various national laboratories have been delving into quantum mechanics, including practical applications of quantum entanglement, for years now and have invested millions of dollars in the development of the quantum internet.
While not possible, quantum networks take advantage of particle properties to encode data more efficiently than is possible using the binary zeros and ones used in traditional computing. At least that’s the idea, anyway.
While efforts to build quantum networks are still in their infancy, several experiments have shown promising results. In 2019, Brookhaven demonstrated entangled photon transfer over a fiber network that spans approximately 11 miles. At the time, it was the longest-distance quantum entanglement experiment taking place in the United States.
More recently, researchers in the Netherlands have demonstrated the transmission of quantum information using an intermediate node, a feature they say is essential for enabling the quantum internet. ®