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In quantum entanglement first, scientists link distant large objects
Physicists create quantum entanglement, making two distant objects behave as one.
Scientists entangled two large quantum objects, both at different locations from each other, in a quantum mechanics first. The feat is a step towards practical application of a rather counterintuitive phenomenon and was accomplished by a team from the Niels Bohr Institute at the University of Copenhagen.
Entanglement is the magical-sounding concept, dubbed "spooky action at a distance" by Einstein. It involves a link is made between two objects that can make them behave like one. This technique is of paramount importance to quantum communication and quantum sensing, explained the University's press release.
The researchers, led by Professor Eugene Polzik, used light particles photons to create an entanglement between a mechanical oscillator ("a vibrating dielectric membrane") and a cloud of atoms, with each acting like a tiny magnet or "spin". They picked these particular objects because atoms can be made to process quantum information while the membrane can store that information.
"With this new technique, we are on route to pushing the boundaries of the possibilities of entanglement," stated professor Polzik. "The bigger the objects, the further apart they are, the more disparate they are, the more interesting entanglement becomes from both fundamental and applied perspectives. With the new result, entanglement between very different objects has become possible."
By entangling the systems, the scientists made them move in correlation with each other. If one object went left, so did the other.
The achievement can pave the way to new sensing technologies. One example would be getting rid of noisy fluctuations currently affecting the Laser Interferometer Gravitational-wave Observatory (LIGO), which detects gravity waves. If the researchers were able to take information from one system and apply it in another, they could get more precise readings.
While the new technology is promising, research into creating useable devices based on quantum mechanics is very challenging, as explained by Ph.D. student Christoffer Østfeldt:
"Imagine the different ways of realizing quantum states as a kind of zoo of different realities or situations with very different qualities and potentials," he shared.
If one was to try to make a device using quantum states that would all have different functions, "it will be necessary to invent a language they are all able to speak. The quantum states need to be able to communicate, for us to use the full potential of the device. That's what this entanglement between two elements in the zoo has shown we are now capable of," Østfeldt added.
Check out the new study in Nature Physics.
The team caught a glimpse of a process that takes 18,000,000,000,000,000,000,000 years.
- In Italy, a team of scientists is using a highly sophisticated detector to hunt for dark matter.
- The team observed an ultra-rare particle interaction that reveals the half-life of a xenon-124 atom to be 18 sextillion years.
- The half-life of a process is how long it takes for half of the radioactive nuclei present in a sample to decay.
Humans are particularly prone to shiver when a group does or thinks the same thing at the same time.
A few years ago, I proposed that the feeling of cold in one's spine, while for example watching a film or listening to music, corresponds to an event when our vital need for cognition is satisfied.
A growing body of research suggests COVID-19 can cause neurological damage in some patients.
- The study examined data of cognitive performance collected from more than 84,000 people, more than 12,000 of whom had likely contracted and recovered from COVID-19.
- Compared to healthy participants, the COVID-19 group performed significantly worse on cognitive tests.
- Mental decline in the worst cases were the equivalent of ageing by 10 years.
The effect size of cognitive deficits varied across three cognitive domains, which were estimated by applying principal component analysis with varimax rotation to the nine test summary scores.
Hampshire et al.<p>Participants who suffered the most severe cases of COVID-19, and had to be put on a respirator, showed cognitive "equivalent to the average 10-year decline in global performance between the ages of 20 to 70." For comparison, the study notes that the difference in cognitive performance between this group and the control "equates to an 8.5-point difference in IQ."<br></p><p>The COVID-19 group scored particularly low on tests measuring semantic problem solving and visual selective attention.</p><p style="margin-left: 20px;">"People who have recovered from COVID-19 infection show particularly pronounced problems in multiple aspects of higher cognitive or 'executive' function, an observation that accords with preliminary reports of executive dysfunction in some patients at hospital discharge," the researchers wrote.</p><p>Considering that all participants had recovered from the disease when they completed the cognitive tests, the results suggest that "COVID-19 infection likely has consequences for cognitive function that persist into the recovery phase," the researchers wrote.</p><p>Still, it's unclear whether these deficits (if indeed caused by COVID-19) are permanent, or how long they may last. But there is evidence suggesting that severe respiratory conditions can cause neurological damage. A <a href="https://link.springer.com/article/10.1186/s13054-019-2626-z" target="_blank">2011 study</a>, for example, found that people who'd been hospitalized with acute respiratory distress syndrome can suffer cognitive deficits that persist up to five years after discharge.</p>
The Block Rearrange test [featured in the Great British Intelligence Test] measures spatial problem solving.
Credit: Hampshire et al.<p>It's worth noting the study is limited, mainly because it didn't compare before-and-after cognitive performance of the COVID-19 group. Another possible limitation: People with lower cognitive abilities may be more likely to contract COVID-19 because they're more likely to put themselves in harm's way.</p><p style="margin-left: 20px;">"We consider such a relationship plausible; however, it would not explain why the observed deficits varied in scale with respiratory symptom severity," the researchers wrote. "We also note that the large and socioeconomically diverse nature of the cohort enabled us to include many potentially confounding variables in our analysis."</p>
San Diego-area hospitals treat coronavirus patients during COVID-19 pandemic
Credit: Mario Tama/Getty Images<p>Only time and further research will tell whether COVID-19 leaves people with lasting cognitive deficits. Scientists are already establishing long-term research projects to answer these questions, such as the <a href="https://www.cambridgebrainsciences.com/studies/covid-brain-study" target="_blank" rel="noopener noreferrer">COVID-19 Brain Study</a>, which aims to monitor the long-term health of 50,000 participants who have tested positive for the disease.</p><p>If you've been diagnosed with COVID-19 and want to enroll in the study, visit <a href="https://www.cambridgebrainsciences.com/studies/covid-brain-study" target="_blank" rel="noopener noreferrer">cambridgebrainsciences.com/studies/covid-brain-study</a>.</p>