Aug 28, 2019
“Qutrit” Experiments Are a First in Quantum Teleportation
Posted by Paul Battista in category: quantum physics
The proof-of-concept demonstrations herald a major step forward in quantum communications.
The proof-of-concept demonstrations herald a major step forward in quantum communications.
You’ve probably heard of Schrödinger’s cat, the unfortunate feline in a box that is simultaneously alive and dead until the box is opened to reveal its actual state. Well, now wrap your mind around Schrödinger’s time, a situation in which one event can simultaneously be the cause and effect of another event.
Then again, maybe not.
In a previous post, I explained why quantum mechanics predicts that there are countless versions of you running around in what could be an infinite number of parallel universes.
This time, I’m going to introduce a controversial proposal by MIT physicist Max Tegmark, that uses these parallel universes to argue that you might actually be immortal.
Gravity was the first fundamental force that humanity recognized, yet it remains the least understood. Physicists can predict the influence of gravity on bowling balls, stars and planets with exquisite accuracy, but no one knows how the force interacts with minute particles, or quanta. The nearly century-long search for a theory of quantum gravity — a description of how the force works for the universe’s smallest pieces — is driven by the simple expectation that one gravitational rulebook should govern all galaxies, quarks and everything in between. [Strange Quarks and Muons, Oh My! Nature’s Tiniest Particles Dissected (Infographic)].
A new high definition radar system that could change the nature of warfare has been demonstrated for the first time. The result, quantum radar, is a high definition detection system that provides a much more detailed image of targets while itself remaining difficult to detect. Quantum radars could provide users with enough detail to identify aircraft, missiles, and other aerial targets by specific model.
According to the MIT Technology Review, researchers at Austria’s Institute of Science and Technology used entangled microwaves to create the world’s first quantum radar system.
Two researchers at Harvard University, Aavishkar A. Patel and Subir Sachdev, have recently presented a new theory of a Planckian metal that could shed light on previously unknown aspects of quantum physics. Their paper, published in Physical Review Letters, introduces a lattice model of fermions that describes a Planckian metal at low temperatures (Tà 0).
Metals contain numerous electrons, which carry electric current. When physicists consider the electrical resistance of metals, they generally perceive it as arising when the flow of current-carrying electrons is interrupted or degraded due to electrons scattering off impurities or off the crystal lattice in the metal.
“This picture, put forth by Drude in 1900, gives an equation for the electrical resistance in terms of how much time electrons spend moving freely between successive collisions,” Patel told Phys.org. “The length of this time interval between collisions, called the ‘relaxation time,’ or ‘electron liftetime,’ is typically long enough in most common metals for the electrons to be defined as distinct, mobile objects to a microscopic observer, and the Drude picture works remarkably well.”
Since their experimental discovery, magnetic skyrmions—tiny magnetic knots—have moved into the focus of research. Scientists from Hamburg and Kiel have now been able to show that individual magnetic skyrmions with a diameter of only a few nanometers can be stabilized in magnetic metal films even without an external magnetic field. They report on their discovery in the journal Nature Communications.
The existence of magnetic skyrmions as particle-like objects was predicted 30 years ago by theoretical physicists, but could only be proven experimentally in 2013. Skyrmions with a diameter from micrometers to a few nanometers were discovered in different magnetic material systems. Although they can be generated on a surface of a few atoms and manipulated with electric currents, they show a high stability against external influences. This makes them potential candidates for future data storage or logic devices. In order to be competitive for technological applications, however, skyrmions must not only be very small, but also stable without an applied magnetic field.
Researchers at the universities of Hamburg and Kiel have now taken an important step in this direction. On the basis of quantum mechanical numerical calculations carried out on the supercomputers of the North-German Supercomputing Alliance (HLRN), the physicists from Kiel were able to predict that individual skyrmions with a diameter of only a few nanometers would appear in an atomically thin, ferromagnetic cobalt film (see Fig. 1). “The stability of the magnetic knots in these films is due to an unusual competition between different magnetic interactions,” says Sebastian Meyer, Ph.D. student in Prof. Stefan Heinze’s research group at the Kiel University.
Yes, we know that sometimes it feels like they just tack the word quantum on new technology and call it a day like we are all living in the Marvel Cinematic Universe. Nevertheless, quantum technology is very real and is just as exciting. Our better understanding of the quantum world and handle on the principals will help us improve everything from computing to encryption.
One of the advantages of the quantum revolution is the ability to sense the world in a new way. The general idea is to use the special properties of quantum mechanics to make measurements or produce images that are otherwise impossible.
Much of this work is done with photons. But as far as the electromagnetic spectrum is concerned, the quantum revolution has been a little one-sided. Almost all the advances in quantum computing, cryptography, teleportation, and so on have involved visible or near-visible light.
Yay face_with_colon_three
Austrian and Chinese scientists have succeeded in teleporting three-dimensional quantum states for the first time. High-dimensional teleportation could play an important role in future quantum computers.
Researchers from the Austrian Academy of Sciences and the University of Vienna have experimentally demonstrated what was previously only a theoretical possibility. Together with quantum physicists from the University of Science and Technology of China, they have succeeded in teleporting complex high-dimensional quantum states. The research teams report this international first in the journal Physical Review Letters.
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