adplus-dvertising
Connect with us

Science

Physicists Observe 'Billions of Billions' of Entangled Electrons | Physics – Sci-News.com

Published

 on


An international team of physicists says they have observed quantum entanglement among ‘billions of billions’ of flowing electrons in thin films of YbRh2Si2, a model strange-metal compound.

In this illustration, one photon (purple) carries a million times the energy of another (yellow). Image credit: NASA / Sonoma State University / Aurore Simonnet.

300x250x1

“Quantum entanglement is the basis for storage and processing of quantum information. At the same time, quantum criticality is believed to drive high-temperature superconductivity,” said co-author Dr. Qimiao Si, a physicist in the Department of Physics and Astronomy at the Center for Quantum Materials at Rice University.

“So our findings suggest that the same underlying physics — quantum criticality — can lead to a platform for both quantum information and high-temperature superconductivity. When one contemplates that possibility, one cannot help but marvel at the wonder of nature.”

In their experiments, Dr. Si and colleagues examined the electronic and magnetic behavior of YbRh2Si2 as it both neared and passed through a critical transition at the boundary between two well-studied quantum phases.

To get the result, the researchers overcame several challenges.

First, they had to develop a highly complex materials synthesis technique to produce ultrapure films of YbRh2Si2.

At absolute zero temperature, the material undergoes a transition from one quantum phase that forms a magnetic order to another that does not. The authors performed terahertz spectroscopy experiments on the films at temperatures as low as 1.4 Kelvin.

The terahertz measurements revealed the optical conductivity of the YbRh2Si2 films as they were cooled to a quantum critical point that marked the transition from one quantum phase to another.

“With strange metals, there is an unusual connection between electrical resistance and temperature,” said senior author Dr. Silke Bühler-Paschen, a physicist in the Institute for Solid State Physics at Technischen Universität Wien and the Department of Physics and Astronomy at the Center for Quantum Materials at Rice University.

“In contrast to simple metals such as copper or gold, this does not seem to be due to the thermal movement of the atoms, but to quantum fluctuations at the absolute zero temperature.”

Atomic-resolution STEM image of the interface between film (top left) and substrate (bottom left), representative enlarged views with simulated overlays (center), and the corresponding unit cells (right). Image credit: Prochaska et al, doi: 10.1126/science.aag1595.

Atomic-resolution STEM image of the interface between film (top left) and substrate (bottom left), representative enlarged views with simulated overlays (center), and the corresponding unit cells (right). Image credit: Prochaska et al, doi: 10.1126/science.aag1595.

To measure optical conductivity, the team shined coherent electromagnetic radiation in the terahertz frequency range on top of the films and analyzed the amount of terahertz rays that passed through as a function of frequency and temperature.

The experiments revealed frequency over temperature scaling, a telltale sign of quantum criticality.

Making the films was even more challenging. To grow them thin enough to pass terahertz rays, the scientists developed a unique molecular beam epitaxy system and an elaborate growth procedure.

Ytterbium, rhodium and silicon were simultaneously evaporated from separate sources in the exact 1-2-2 ratio. Because of the high energy needed to evaporate rhodium and silicon, the system required a custom-made ultrahigh vacuum chamber with two electron-beam evaporators.

“Our wild card was finding the perfect substrate: germanium,” said first author Lukas Prochaska, a graduate student in the Institute for Solid State Physics at Technischen Universität Wien.

“The germanium was transparent to terahertz, and had certain atomic distances (that were) practically identical to those between the ytterbium atoms in YbRh2Si2, which explains the excellent quality of the films.”

“Conceptually, it was really a dream experiment,” Dr. Si said.

“Probe the charge sector at the magnetic quantum critical point to see whether it’s critical, whether it has dynamical scaling.”

“If you don’t see anything that’s collective, that’s scaling, the critical point has to belong to some textbook type of description. But, if you see something singular, which in fact we did, then it is very direct and new evidence for the quantum entanglement nature of quantum criticality.”

The results appear in the journal Science.

_____

L. Prochaska et al. 2020. Singular charge fluctuations at a magnetic quantum critical point. Science 367 (6475): 285-288; doi: 10.1126/science.aag1595

Let’s block ads! (Why?)

728x90x4

Source link

Continue Reading

Science

Marine plankton could act as alert in mass extinction event: UVic researcher – Langley Advance Times

Published

 on


A University of Victoria micropaleontologist found that marine plankton may act as an early alert system before a mass extinction occurs.

With help from collaborators at the University of Bristol and Harvard, Andy Fraass’ newest paper in the Nature journal shows that after an analysis of fossil records showed that plankton community structures change before a mass extinction event.

“One of the major findings of the paper was how communities respond to climate events in the past depends on the previous climate,” Fraass said in a news release. “That means that we need to spend a lot more effort understanding recent communities, prior to industrialization. We need to work out what community structure looked like before human-caused climate change, and what has happened since, to do a better job at predicting what will happen in the future.”

300x250x1

According to the release, the fossil record is the most complete and extensive archive of biological changes available to science and by applying advanced computational analyses to the archive, researchers were able to detail the global community structure of the oceans dating back millions of years.

A key finding of the study was that during the “early eocene climatic optimum,” a geological era with sustained high global temperatures equivalent to today’s worst case global warming scenarios, marine plankton communities moved to higher latitudes and only the most specialized plankton remained near the equator, suggesting that the tropical temperatures prevented higher amounts of biodiversity.

“Considering that three billion people live in the tropics, the lack of biodiversity at higher temperatures is not great news,” paper co-leader Adam Woodhouse said in the release.

Next, the team plans to apply similar research methods to other marine plankton groups.

Read More: Global study, UVic researcher analyze how mammals responded during pandemic

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Science

Scientists Say They Have Found New Evidence Of An Unknown Planet… – 2oceansvibe News

Published

 on


In the new work, scientists looked at a set of trans-Neptunian objects, or TNOs, which is the technical term for those objects that sit out at the edge of the solar system, beyond Neptune

The new work looked at those objects that have their movement made unstable because they interact with the orbit of Neptune. That instability meant they were harder to understand, so typically astronomers looking at a possible Planet Nine have avoided using them in their analysis.

Researchers instead looked towards those objects and tried to understand their movements. And, Dr Bogytin claimed, the best explanation is that they result from another, undiscovered planet.

300x250x1

The team carried out a host of simulations to understand how those objects’ orbits were affected by a variety of things, including the giant planets around them such as Neptune, the “Galactic tide” that comes from the Milky Way, and passing stars.

The best explanation was from the model that included Planet 9, however, Dr Bogytin said. They noted that there were other explanations for the behaviour of those objects – including the suggestion that other planets once influenced their orbit, but have since been removed – but claim that the theory of Planet 9 remains the best explanation.

A better understanding of the existence or not of Planet 9 will come when the Vera C Rubin Observatory is turned on, the authors note. The observatory is currently being built in Chile, and when it is turned on it will be able to scan the sky to understand the behaviour of those distant objects.

Planet Nine is theorised to have a mass about 10 times that of Earth and orbit about 20 times farther from the Sun on average than Neptune. It may take between 10,000 and 20,000 Earth years to make one full orbit around the Sun.

You may be tempted to ask how an entire planet could ‘hide’ in our solar system when we have zooming capabilities such as the new iPhone 15 has, but consider this: If Earth was the size of a marble, the edge of our solar system would be 11 kilometres away. That’s a lot of space to hide a planet.

[source:independent]

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Science

Dragonfly: NASA Just Confirmed The Most Exciting Space Mission Of Your Lifetime – Forbes

Published

 on


NASA has confirmed that its exciting Dragonfly mission, which will fly a drone-like craft around Saturn’s largest moon, Titan, will cost $3.35 billion and launch in July 2028.

Titan is the only other world in the solar system other than Earth that has weather and liquid on the surface. It has an atmosphere, rain, lakes, oceans, shorelines, valleys, mountain ridges, mesas and dunes—and possibly the building blocks of life itself. It’s been described as both a utopia and as deranged because of its weird chemistry.

Set to reach Titan in 2034, the Dragonfly mission will last for two years once its lander arrives on the surface. During the mission, a rotorcraft will fly to a new location every Titan day (16 Earth days) to take samples of the giant moon’s prebiotic chemistry. Here’s what else it will do:

300x250x1
  • Search for chemical biosignatures, past or present, from water-based life to that which might use liquid hydrocarbons.
  • Investigate the moon’s active methane cycle.
  • Explore the prebiotic chemistry in the atmosphere and on the surface.

Spectacular Mission

“Dragonfly is a spectacular science mission with broad community interest, and we are excited to take the next steps on this mission,” said Nicky Fox, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. “Exploring Titan will push the boundaries of what we can do with rotorcraft outside of Earth.”

It comes in the wake of the Mars Helicopter, nicknamed Ingenuity, which flew 72 times between April 2021 and its final flight in January 2023 despite only being expected to make up to five experimental test flights over 30 days. It just made its final downlink of data this week.

Dense Atmosphere

However, Titan is a completely different environment to Mars. Titan has a dense atmosphere on Titan, which will make buoyancy simple. Gravity on Titan is just 14% of the Earth’s. It sees just 1% of the sunlight received by Earth.

function loadConnatixScript(document)
if (!window.cnxel)
window.cnxel = ;
window.cnxel.cmd = [];
var iframe = document.createElement(‘iframe’);
iframe.style.display = ‘none’;
iframe.onload = function()
var iframeDoc = iframe.contentWindow.document;
var script = iframeDoc.createElement(‘script’);
script.src = ‘//cd.elements.video/player.js’ + ‘?cid=’ + ’62cec241-7d09-4462-afc2-f72f8d8ef40a’;
script.setAttribute(‘defer’, ‘1’);
script.setAttribute(‘type’, ‘text/javascript’);
iframeDoc.body.appendChild(script);
;
document.head.appendChild(iframe);

loadConnatixScript(document);

(function()
function createUniqueId()
return ‘xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx’.replace(/[xy]/g, function(c) 0x8);
return v.toString(16);
);

const randId = createUniqueId();
document.getElementsByClassName(‘fbs-cnx’)[0].setAttribute(‘id’, randId);
document.getElementById(randId).removeAttribute(‘class’);
(new Image()).src = ‘https://capi.elements.video/tr/si?token=’ + ’44f947fb-a5ce-41f1-a4fc-78dcf31c262a’ + ‘&cid=’ + ’62cec241-7d09-4462-afc2-f72f8d8ef40a’;
cnxel.cmd.push(function ()
cnxel(
playerId: ’44f947fb-a5ce-41f1-a4fc-78dcf31c262a’,
playlistId: ‘aff7f449-8e5d-4c43-8dca-16dfb7dc05b9’,
).render(randId);
);
)();

The atmosphere is 98% nitrogen and 2% methane. Its seas and lakes are not water but liquid ethane and methane. The latter is gas in Titan’s atmosphere, but on its surface, it exists as a liquid in rain, snow, lakes, and ice on its surface.

COVID-Affected

Dragonfly was a victim of the pandemic. Slated to cost $1 billion when it was selected in 2019, it was meant to launch in 2026 and arrive in 2034 after an eight-year cruise phase. However, after delays due to COVID, NASA decided to compensate for the inevitable delayed launch by funding a heavy-lift launch vehicle to massively shorten the mission’s cruise phase.

The end result is that Dragonfly will take off two years later but arrive on schedule.

Previous Visit

Dragonfly won’t be the first time a robotic probe has visited Titan. As part of NASA’s landmark Cassini mission to Saturn between 2004 and 2017, a small probe called Huygens was despatched into Titan’s clouds on January 14, 2005. The resulting timelapse movie of its 2.5 hours descent—which heralded humanity’s first-ever (and only) views of Titan’s surface—is a must-see for space fans. It landed in an area of rounded blocks of ice, but on the way down, it saw ancient dry shorelines reminiscent of Earth as well as rivers of methane.

The announcement by NASA makes July 2028 a month worth circling for space fans, with a long-duration total solar eclipse set for July 22, 2028, in Australia and New Zealand.

Wishing you clear skies and wide eyes.

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Trending