Next stop: the desk of President Trump.
The U.S. is ready to invest big in quantum computing.
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Category: quantum physics
Researchers from the Moscow Institute of Physics and Technology, ETH Zurich, and Argonne National Laboratory, U.S, have described an extended quantum Maxwell’s demon, a device locally violating the second law of thermodynamics in a system located 1–5 meters away from the demon. The device could find applications in quantum computers and microscopic refrigerators cooling down tiny objects with pinpoint accuracy. The research was published Dec. 4 in Physical Review B.
The second law says that the entropy — that is, the degree of disorder or randomness — of an isolated system never decreases.
“Our demon causes a device called a qubit to transition into a more orderly state,” explained the study’s lead author Andrey Lebedev of MIPT and ETH Zurich. “Importantly, the demon does not alter the qubit’s energy and acts over a distance that is huge for quantum mechanics.”
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https://paper.li/e-1437691924#/
A team of researchers from Austria, Italy and Sweden has successfully demonstrated teleportation using on-demand photons from quantum dots. In their paper published in the journal Science Advances, the group explains how they accomplished this feat and how it applies to future quantum communications networks.
Scientists and many others are very interested in developing truly quantum communications networks—it is believed that such networks will be safe from hacking or eavesdropping due to their very nature. But, as the researchers with this new effort point out, there are still some problems standing in the way. One of these is the difficulty in amplifying quantum signals. One way to get around this problem, they note, is to generate photons on-demand as part of a quantum repeater—this helps to effectively handle the high clock rates. In this new effort, they have done just that, using semiconductor quantum dots.
Prior work surrounding the possibility of using semiconductor quantum dots has shown that it is a feasible way to demonstrate teleportation, but only under certain conditions, none of which allowed for on-demand applications. Because of that, they have not been considered a push-button technology. In this new effort, the researchers overcame this problem by creating quantum dots that were highly symmetrical using an etching method to create the hole pairs in which the quantum dots develop. The process they used was called a XX (biexciton)–X (exciton) cascade. They then employed a dual-pulsed excitation scheme to populate the desired XX state (after two pairs shed photons, they retained their entanglement). Doing so allowed for the production of on-demand single photons suitable for use in teleportation. The dual pulsed excitation scheme was critical to the process, the team notes, because it minimized re-excitation.
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IonQ, one of many companies developing a quantum computer, has announced a new trapped ion quantum computer with 79 processing qubits. The company claims this quantum computer should beat Google’s 72-qubit quantum computer, not just in terms of number of qubits, but also in total processing performance.
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MIT researchers invented a method of shrinking objects to the nanoscale.
The team can generate structures one-thousandth the volume of the original using a variety of materials, including metals, quantum dots, and DNA.
Existing techniques—like etching patterns onto a surface with light—work for 2D nanostructures, but not 3D. And while it’s possible to make 3D nanostructures, the process is slow, challenging, and restrictive.
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The concept of teleportation comes primarily from science fiction literature throughout human history, but things are changing. It’s 2015 and developments in quantum theory and general relativity physics have been successful in exploring the concept of teleportation for quite some time now.
Today, numerous teleportation breakthroughs have been made. One example is the work of Professor Rainer Blatt, at the University of Innsbruck. They were successfully able to perform teleportation on atoms for the first time, their work was published in the journal Nature. They were able to transfer key properties of one particle to another without using any physical link. In this case, teleportation occurred in the form of transferring quantum states between two atoms, these include the atom’s energy, motion, magnetic field and other physical properties. This is possible due to the strange behavior that exists at the atomic scale, known as entanglement. It’s what Einstein referred to as a “spooky action.”
Another study was published by a team of University of Queensland physicists in the journal Nature in 2013 demonstrating the successful teleportation with solid state systems. A process by which, again, quantum information can be transmitted from one place to another without sending a physical carrier of information. This is the same concept, and is made possible through the phenomenon of entanglement.
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