Besides getting treatment for her back injury, Williams said she also received therapy since giving birth, and it was after she lost the 2018 U.S. Open to Naomi Osaka. The mother of one said she sent an apology letter to Osaka, and it took her some time to return to tennis. Serena Williams talked about when she plans to retire during a recent panel discussion. (Photo: Clive Brunskill/Getty Images Sport via Getty Images) For example, she had to drop out of the Rogers Cup and the Cincinnati Masters due to a back injury, and despite making it to four Grand Slam finals since giving birth, she hasn’t won a title yet. Osaka then responded to Williams and wrote: “People can misunderstand anger for strength because they can’t differentiate between the two,” she wrote. “No one has stood up for themselves the way you have and you need to continue trailblazing.” “[I plan to] transfer out, you know, in 20 years,” said Williams about retirement, according to Yahoo. Her words were met with cheers. Serena Williams has faced some on-the-court challenges since she delivered her daughter Alexis Olympia Ohanian Jr. on Sept. 1, 2017. Williams was hit with violations on that day, after she argued with the umpire’s call and broke her racket. And during the trophy ceremony, the crowd booed Osaka since they seemed to be on Williams’ side. It’s something she revealed Wednesday during a panel discussion for Advertising Week New York, and reportedly Williams wants to win her 24th Grand Slam title, which would tie a record established by Australian tennis player Margaret Court. “Days passed, and I still couldn’t find peace,” wrote Williams in an essay for Harper’s Bazaar. “I started seeing a therapist. I was searching for answers, and although I felt like I was making progress, I still wasn’t ready to pick up a racket.” But that hasn’t seemed to discourage Williams, and at 38 she said retirement isn’t in her immediate plans.
© 2018 Phys.org Quantum memories are devices that can store quantum information for a later time, which are usually implemented by storing and re-emitting photons with certain quantum states. But often it’s difficult to tell whether a memory is storing quantum or merely classical information. In a new paper, physicists have developed a new test to verify the quantum nature of quantum memories. More information: Denis Rosset, Francesco Buscemi, and Yeong-Cherng Liang. “Resource Theory of Quantum Memories and Their Faithful Verification with Minimal Assumptions.” Physical Review X. DOI: 10.1103/PhysRevX.8.021033 The new test uses a semiquantum framework that is very similar to that used in some tests of entanglement in quantum states, in which the entanglement refers to correlations in space, in contrast to the time-like entanglement in quantum memories. Conventional protocols for testing for space-like correlations often use two characters, Alice as the sender and Bob as the receiver of quantum states. But since quantum memories involve time-like correlations, the protocol needs only a single character, whom the researchers call Abby, to act as both the sender and receiver at different times. In the test proposed in the new study, by comparing the relative frequencies of the signals that Abby sends and receives, it is possible to estimate the time-like entanglement and therefore certify that a quantum memory can store quantum information.The researchers showed that the new test is robust against noise and losses, and they expect that it should be possible to experimentally perform the test with current technology. The test would then provide a very useful tool for the future development of quantum memories.”In the development of novel quantum technologies, it’s crucial that there exists a reliable way to benchmark the relevant components and make sure that they function as expected,” Liang said. “Our findings provide a way to certify one of the most important features of these components while making sure that we are not making more assumptions than necessary. With these tests, we hope that it simplifies the quality control procedures of quantum devices while not falling into the trap of making unjustifiable assumptions.” Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Journal information: Physical Review X Citation: How can you tell if a quantum memory is really quantum? (2018, May 23) retrieved 18 August 2019 from https://phys.org/news/2018-05-quantum-memory.html (i) Although the inner workings of a quantum memory are hidden from view, if a memory can be simulated by measurement and state preparation (corresponding to entanglement-breaking channels) as shown in (ii), then the memory is not genuinely quantum. Credit: Rosset et al. Published by the American Physical Society Physicists use quantum memory to demonstrate quantum secure direct communication The researchers, Denis Rosset, Francesco Buscemi, and Yeong-Cherng Liang, have published a paper on the quantum memory test in a recent issue of Physical Review X.”Quantum memories are indispensable components of long-distance quantum communication networks and potentially even in a full-scale quantum computer,” Liang, a physicist at National Cheng Kung University in Taiwan, told Phys.org. “For these components to serve their purpose, it’s essential that they can preserve, at least, the quantum entanglement between certain inputs to the memory and whatever other parts that did not enter the memory. Our work strikes the right balance in certifying any device that possesses this ability while making the minimal assumptions.”As the scientists explain, the quantum entanglement between the system stored in the memory and any remote systems not in the memory must be maintained for the entire storage time. If this entanglement is broken at any time, then the device no longer functions as a quantum memory but rather as an “entanglement-breaking channel” and as a result can transmit only classical information. Although currently there are tests that can verify the quantum nature of a quantum memory, these tests have certain limitations. For one, they require the experimenter to trust that the measurement and state preparation devices used by the quantum memory are accurate. For this reason, these tests are called device-dependent protocols. However, a test that makes no assumptions cannot be “faithful,” meaning it may overlook some genuine quantum memories. This is because these methods test for the violation of a Bell inequality as verification of entanglement, which is sufficient but not necessary, as some genuinely quantum channels do not violate Bell inequalities and so would not pass this test.Although it would be ideal to design a test that is completely device-independent, the researchers explain that it is not possible to test a single memory in this manner, even in principle, due to the need to test the quantum memory at two different times. However, their new test is measurement-device-independent, meaning it still requires the state preparation device to be trusted, but no assumptions need to be made regarding the measurement device. The new test is also faithful, meaning it can correctly identify all quantum memories that function as non-entanglement-breaking quantum channels.
Forgetting can be the result of an active deletion process in the brain rather than a failure to remember —a mechanism that helps us adapt our behaviour according to the surroundings, says a new study. The findings could point towards new ways of tackling memory loss associated with conditions such as Alzheimer’s disease and other types of dementia.“Our study looks at the biological processes that happen in the brain when we forget something,” said Oliver Hardt from University of Edinburgh in Scotland. “The next step is to work out why some memories survive whilst others are erased. If we can understand how these memories are protected, it could one day lead to new therapies that stop or slow pathological memory loss,” Hardt said. Also Read – ‘Playing Jojo was emotionally exhausting’The findings were published in The Journal of Neuroscience. The study conducted in rats could also help scientists to understand why some unwanted memories are so long-lasting such as those of people suffering from post-traumatic stress disorders.Memories are maintained by chemical signalling between brain cells that rely on specialised receptors called AMPA receptors. The more AMPA receptors are on the surface where brain cells connect, the stronger the memory.