Entanglement on demand

first_img Citation: Entanglement on demand (2008, April 7) retrieved 18 August 2019 from https://phys.org/news/2008-04-entanglement-demand.html One of the problems in quantum information processing is inefficiency. Photon entanglement is generally considered a leading candidate for quantum computing (it is used for teleportation and cryptography), but right now it is sort of a hit and miss proposition. “The only methods we have for generating entangled photons are random,” Yosi Avron tells PhysOrg.com. “You don’t always get an entangled pair, and when you do, after you test the photons, they are useless.” 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.center_img Avron, a physicist at the Technion-Israel Institute of Technology, believes that he and his colleagues may have found a technique that could solve this problem of photon entanglement. Avron worked with Gershoni, Bisker, Lindner and Meirom at Technion-Israel, as well as Warburton at Heriot-Watt University in Edinburgh. The team’s scheme revolves around time reordering, and is explained in Physical Review Letters: “Entanglement on Demand through Time Reordering.”“The key is something called switch path ambiguity,” explains Avron. He points out that in quantum mechanics, a particle can be in two places at once. “If you have two slits on a paper, and you send a photon toward them, the photon can go through both at once. It doesn’t have to choose. If you have a screen behind these two slits, the interference pattern that shows is the same behind each slit. The photon went through both.”Avron goes on to explain that the key is in setting up different paths for the photons to follow, and in creating a situation in which two states give the same result. In that way, it would be possible to produced entangled photons on demand, rather than using hit and miss:“If you have a system with an atom, you start it in an excited state. Then it relaxes and releases a photon at an intermediate state. Then it relaxes more and releases a photon at the ground state. The ambiguity comes in when we create a second intermediate state, identical to the first, so that you have a state where two photons are generated in alternative ways.”It sounds nice, but Avron acknowledges that this where more problems arise. “It is difficult to get two states that are precisely identical like that,” he says. “The states have slightly different energies and this adversely affects entanglement.” The solution the team came up with was to re-arrange the timing of the system. “This is not a new idea,” he qualifies, “but we were the first to create a believable theory of how it could be done.” “All we have to do is reorder one of the paths,” Avron explains. “And if you do, then you could get a situation where you get entanglement because the states become identical…Instead of matching in each generation of photons, it is possible to match across generations and reorder them. Quantum mechanics allows for this without penalty.”Avron is careful to point out that at this stage the results are theoretical. “But,” he continues, “we think that it is possible to design an experiment to test it. David Gershoni is working on such an experiment.”The experiment may take one or two years to get done, but Avron is confident of the results. “It has been difficult to get high quality entanglement on demand,” he explains, “and what we have discovered is that it is possible and something that we can do in a few years’ time.”Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.last_img read more

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New bus system tops off batteries in just 15 seconds

first_img German city to test viability of inductive charging system on two real bus lines More information: www.tosa2013.com/en#/tosa2013 (Phys.org) —A new type of battery bus system being tested in Switzerland is able to operate continually by making use of flash-charging stations. Called Trolleybus Optimisation Systeme Alimentation (TOSA), the new bus and recharging system is currently being tested on a one mile route in Geneva between the city’s airport and international exhibition center. © 2013 Phys.org The system is designed to allow for quickly “topping off” batteries at bus stops, with a longer charge of just three to four minutes between bus runs. Buses are equipped with a laser controlled arm that sits atop the bus and automatically guides the contact mechanism to its mate in an overhanging charging station. Passengers get on and off the bus just as they would any other bus.The system was designed by Zurich based electronics giant ABB with assistance from Geneva Public Transport and other city agencies. The TOSA system flash charges at a rate of 400 kW, allowing batteries to be topped off in just 15 seconds every few stops. Officials describing the system call it a truly zero-carbon emission system because the electricity to recharge the buses is generated using hydroelectricity. They noted also that such a bus system would be a big improvement over conventional electric buses that get their power from overhead lines and also other battery run buses that must be taken out of service periodically for recharging. They claim also that despite such frequent recharging, the batteries in the buses are expected to last for at least a decade. The TOSA system, two years in the making, was designed to be used in areas of heavy congestion, where ridership would be high—the test bus is 19 meters long and can hold 135 passengers. The test run of the system is designed to highlight potential problems with the system to allow for improvements to be made. Once that happens, ABB plans to sell the system to other cities around the world—that could mean the end of loud diesel buses spewing smoke or overhead electrical lines cluttering the view from the street. ABB also says that its system is more cost-effective than other mass transportation systems and more flexible as well because it allows for different types of designs for the charging stations. 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. Citation: New bus system tops off batteries in just 15 seconds (2013, June 4) retrieved 18 August 2019 from https://phys.org/news/2013-06-bus-tops-batteries-seconds.htmllast_img read more

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Water circling drain experiments offer insight into black holes

first_img Explore further A small international team of researchers has found that water waves created due to scattering from a spinning vortex can show rotational superradiance—an effect astrophysicists have predicted likely to occur in black holes, but which has never been replicated in a lab experiment. In their paper published in the journal Nature Physics, the group explains how they observed and measured waves propagating on the surface of water near a draining vortex and what they found. © 2017 Phys.org Researchers uncover new gravitational wave characteristics This artist’s concept depicts a supermassive black hole at the center of a galaxy. The blue color here represents radiation pouring out from material very close to the black hole. The grayish structure surrounding the black hole, called a torus, is made up of gas and dust. Credit: NASA/JPL-Caltech As the researchers explain, when a wave strikes an obstacle, it tends to scatter, as can be observed at virtually any seashore. But more difficult to see is that some of the wave is reflected as well as partially transmitted. This led to a theory back in 1954 by Robert Dicke that suggests if an object is spinning, the waves can be amplified by extracting energy from the parts of the wave that are scattered—a phenomenon called superradiance. In this new effort, the researchers conducted experiments designed to prove the theory correct.The experiments consisted of placing water in a 3 x 1.5 meter tank with a 4 cm hole at the center to serve as a drain—the researchers took measurements of wave activity by sensors mounted on the side of the tank (and by a high-speed, three-dimensional air–fluid interface sensor) as pumped-in water was drained, creating a vortex. The researchers report that they observed waves propagating on the surface and that measurements confirmed the waves were amplified after scattering occurred. They further report that the largest amplification recorded was 14 percent +/– 8 percent with waves of 3.70Hz in water that was just 6.25 cm deep. They claim their findings agree with theory, and therefore that their findings can be applied to research surrounding black holes. This is because they believe the scattering of shallow waves on water is analogous to the action that occurs at the event horizon of a black hole. They also note that new, more sensitive gravitational wave detectors might someday be able to measure roughly the same behavior with real black holes.Press release from University of Nottinghamcenter_img Journal information: Nature Physics 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. Citation: Water circling drain experiments offer insight into black holes (2017, June 14) retrieved 18 August 2019 from https://phys.org/news/2017-06-circling-insight-black-holes.html More information: Theo Torres et al. Rotational superradiant scattering in a vortex flow, Nature Physics (2017). DOI: 10.1038/nphys4151last_img read more

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Researchers find electron current direction in photondrag effect is dependent on surrounding

first_imgA team of researchers at the U.S. National Institute for Standards and Technology has found that electron current flow direction produced by the photon-drag effect is dependent on the environment in which a metal is sitting. In their paper published in Physical Review Letters, the group describes experiments they conducted with polarized light striking a gold film and what they learned. Explore further Corkscrew photons may leave behind a spontaneous twist More information: Jared H. Strait et al. Revisiting the Photon-Drag Effect in Metal Films, Physical Review Letters (2019). DOI: 10.1103/PhysRevLett.123.053903 Figure 1: Linear photon-drag effect, Gibson model. © 2019 Science X Networklast_img read more

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Fikry might have been indifferent to my work

first_imgGabrielle Zevin’s The Collected Works of A.J. Fikry is one of the most beautiful books I have read in a long long time. It doesn’t pander to baseless emotions to make the thoughts and feelings work, nor does it deal in excesses. The story of book shop owner A.J Fikry and how his life changes with the sudden entrance of a child he adopts and names Maya, flows out as incredibly as the stories of the books he makes Maya read as she grows up. Thus, when it came to interviewing Zevin, I knew I would not miss it for the world! Read… Also Read – ‘Playing Jojo was emotionally exhausting’Let’s start with a bit about you. Tell us how you started writing.My grandmother had an electric typewriter that I was obsessed with as a little girl. When we would visit her, she would always set me up with paper, and I’d spend hours and hours typing a few words, basically nonsense. I liked the satisfying clatter of the keys and the scent of ink on paper. I always tell people that before I liked to write, I liked to type.How did The Collected Works of A.J. Fikry come into being? Also Read – Leslie doing new comedy special with NetflixSince I was first published almost a decade ago, I’ve wanted to write a book about that experience and the way publishing a novel changes your relationship to books. I played with this novel—my book about books—for many years, but I could never quite work it out. It was originally focused on what would become the Maya character, the fledgling writer. After about seven years, I realized that the book would be much better if it were about the bookseller and not the writer. And once I knew that, the writing went very quickly!  And A.J Fikry. How did he come about? Were you inspired by someone into creating this character? At nearly every bookstore I go to, someone tells me that they know a person just like A.J. Fikry. But no, he wasn’t consciously based on anyone. There are many A.J.’s in all aspects of bookselling and publishing. And even when these people aren’t fans of my books, I don’t mind them. We need A.J.’s. There are A LOT of books published every year, and we need people to tell us what is good and what is not. My dad, who I adore, is probably a bit of an A.J. He is a runner like A.J., and he has many, many, many opinions. My mom, incidentally, is a bit of an Amelia. She always studies the menus before she goes to restaurants. Besides A.J who is your favourite character? I’ll make it a little harder – besides Maya as well! Probably poor Daniel Parish. The first time someone called him a villain at an event I was doing, I remember feeling a bit sad. I know his shortcomings, but I have empathy for him. For many years, the most successful book I published was the first one, the one I wrote when I was 25. Daniel has a similar backstory though I should mention that my personal life is a lot less complicated than his.The books A.J notes down for his daughter – are those books that made an impact on you some way or the other? Are they your favourites?They are not my favorites, and I wouldn’t necessarily say they were A.J.’s either. They are a broad selection of short stories that A.J. thinks would be instructive for a young writer to have read: a mini-cannon. But the truth is, that’s only what the stories are from A.J’s point of view. From my point of view as the novelist, the stories had to do quite a few other things as well. They had to provide a way for A.J. to tell Maya about his life. They had to work thematically with the events of the novel. They had to be good chapter titles, too! And so I will tell you that the business of choosing them was quite complicated. If they aren’t – what are yours? And what would your comprehensive list of ‘what-my-daughter-must-read’ look like?Oh, my favorites change all the time! I’m always finding new favorites. My three favorite books I read this year were The Interestings by Meg Wolitzer, The Dinner by Herman Koch, and Flora and Ulysses by Kate DiCamillo.  It’s funny. I feel like a lively reading life should include a degree of randomness, a degree of discovery. So…I probably wouldn’t make a list like A.J.’s in the first place. I do think short stories are a good place to start with young writers (and readers), though. My list would probably include more female writers, more twenty-first century, more genre. A.J. doesn’t have, for instance, any sci-fi. When I was a kid, one of my favorite short stories was Ray Bradbury’s The Veldt. It’s an early virtual reality story, and I remember that it blew my tiny child mind. There’s a list A.J. makes for Maya when she has writer’s block. That list, which includes Z.Z. Packer and Amy Hempel, is closer to my taste. Tell us about the best and the worst times you faced while writing this book. Once a book is finished, I have the mysterious ability to block out almost the entire process of writing it. I know I’ve done a good job when I’m finished writing, and I feel a sense of loss. I know I’ve done a good job when I feel like the characters are people I used to know, but who I won’t be seeing anymore. Anyway, I sometimes find it hard when I’m finished to move on to the next thing! I But in a way, this is the best and the worst part. You are always meeting new colleagues and having to say goodbye.Would your book make the cut at A.J’s bookshop?Depends on what day it crossed A.J.’s desk and what kind of mood he was in. Depends on how much the sales rep sold it to him and how much he trusted his or her opinion. As I was writing, I knew that A.J. would probably not have read anything I had written and if he had, he wouldn’t necessarily have liked it anyway. I made peace with A.J.’s indifference to my work very early on in the process. A delightful discovery for me has been that it is not required for all your characters to approve of you. Someone said to me that the A.J. of the beginning of the story would not like the book, but the A.J. at the end might. I agree with this assessment.last_img read more

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Celebrating Innocence

first_imgThe 12th edition of National School of Drama’s Jashnebachpan- the biggest children theatre festival, is here to enthrall children from all walks of life including the underprivileged. Over 1000 underprivileged children from Delhi NCR area witnessed the commencement ceremony in the NSD campus. NSD has also roped in Zonal Cultural Centers  to further encourage and support regional participation.Jashnebachpan 2014 was inaugurated by Shripad Yasso Naik, Minister of Tourism and Culture on Sunday, 2 November at Abhimanch in the Capital’s National School of Drama. The inaugural ceremony was followed by Bal Rang, a performance of various artists was guided by Laique Hussain. This performance included participants from various states like Orissa, Punjab, Andhra Pradesh, Gujarat and Delhi.  1000 underprivileged children including girls and boys from various age groups eagerly awaited the ceremony. Also Read – ‘Playing Jojo was emotionally exhausting’Jashnebachpan was started in 1998 by Theatre In Education Company (T.I.E Co.), NSD in order to contribute to the growth and development of children’s theatre across the country, and has now come to be regarded as one of the largest and most important theatre festivals in India for Children. Theatre personality and chairman NSD society Ratan Thiyam inaugurated the festival with Himani Shivpuri renowned theatre and cine actress. T.I.E. Co that has staged over 1200 shows, 350 workshops catering to more than 11 lakhs children with their plays celebrates its glorious 25 years.  Also Read – Leslie doing new comedy special with NetflixCelebrating some of the best children’s flavors and a distinct palate back on stage, every autumn National School of Drama organizes a festival of theatre for children. This year, of Jashnebachpan, from 2 to 14 November, will make sure that children are treated to the best through theatre for children.Jashnebachpan 2014 will be featuring various performances in 8 languages – Assamese, Bengali, English, Kannada, Marathi, Malayalam, Manipuri, Hindi and 1 non-verbal from 14 States/Union Territories at the NSD Campus. Celebrating its Silver Jubilee year, T.I.E. Co. is also organizing its first ever three-day seminar from 12 to 14 November. This three day educational seminar, titled, ‘Theatre for children; who’s need is it?’ will have known theatre personalities like Rudraprasad Sengupta, Feizal Alkazi, Kanchan Sontakke, Bansi Kaul and many more.last_img read more

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Come Norwesters drive against dengue initiated by KMC

first_imgKolkata: The Kolkata Municipal Corporation (KMC) has intensified its drive against Dengue in view of the nor’wester that is hitting the city. The state government has given Rs 3 crore to KMC to carry on with its anti Dengue drive. It may be mentioned that Chief Minister Mamata Banerjee has instructed all civic bodies to take steps to prevent Dengue. At all the administrative review meetings, she has asked senior officials of the district administration to keep the areas under the civic bodies and Panchayats clean. She has also instructed district administration to launch drives to create awareness Dengue. Also Read – Heavy rain hits traffic, flightsThe KMC has intensified the cleaning operation. KMC teams are visiting houses regularly to inspect the overhead tanks and underground reservoirs. If mosquito larvae is found, the owners in case of individual houses and secretary in case of housing cooperatives are asked to take steps to clean the overhead tanks and underground reservoirs. The residents have been asked to clear the containers used to store water once in a week.Debashis Biswas, Chief Vector Control officer of KMC said Aedes Egypti mosquitoes take seven days to complete their life circle, that is, from egg to larvae to pupa and then to adult mosquito. “These seven days are very important. The residents are being requested to clean the containers at least once a week as a safety measure.” Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedAtin Ghosh, member, Mayor-in-Council in charge of health said due to global warming, the breeding season of mosquitoes have changed. To cope with the situation, the KMC is carrying out drives against Dengue throughout the year. “It is not possible for the civic bodies to bring the situation under control. We need cooperation of the residents. They should keep their houses clean and the containers used to store water should be cleaned once in a week. The overhead tanks and underground reservoirs should be properly covered.” The KMC has 15 Dengue detection centres in the city along with 24 Rapid Action teams. The KMC runs free clinics in every ward. KMC doctors said those suffering from fever should visit the Dengue detection centres and get their blood tested free of cost. Not only the centres have trained technicians, proper method is followed to detect Dengue.It may be mentioned that the ministry of Health had lauded the KMC for the anti Dengue drives. Hoardings and posters to crate awareness among the people are put up all over the city. The KMC is also assisting the neighbourding civic bodies of the Bidhannagar Municipal Corporation and south Dum Dum municipality to conduct anti Dengue drives as well.last_img read more

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Dr Asit Kumar Panja bags Young Scientist Award in Literary Research

first_imgKolkata: Dr Asit Kumar Panja, an ayurvedic genius from an obscure village in Bankura’s Joyrambati, who has already set his footprint in the national and international arena for his multifaceted contributions in the field of Ayurveda, has now bagged the prestigious ‘Young Scientist Award’ in the category of Literary Research.The Central Council for Research in Ayurvedic Sciences under the Ministry of Ayush has conferred the award on Dr Panja during a programme in New Delhi on Saturday. Panja, an assistant professor of National Institute of Ayurveda (NIA), Jaipur in Rajasthan has been carrying out research on various aspects of Ayurveda for the past 15 years and has been associated with various research projects of Ayush and World Health Organisation (WHO). Also Read – Heavy rain hits traffic, flightsHe has gone through classical texts and manuscripts of Ayurveda and converted the treasured knowledge into a modern form, exploring the possible ways of implementing the old and pure form of Indians traditional methods of treatment. Research was done on how the classical ways of treatment and diagnosis can be attributed a modern touch. Panja has performed researches on 35 aspects including the coding of ancient Ayurvedic manuscripts. The coding helps in identifying the diseases that had a mention in the ancient literature. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedOne of his remarkable performances is deciphering an old manuscript, “Charaka Bibriti” written by Yogendranath Sen, an ancient scholar of Ayurveda that Panja had got in 2014. He started the research work in 2015. He has analysed the manuscripts critically and published a book of 600 pages containing the substances that had been there in the manuscripts. Being the head of Manuscript segment of the NIA always gives the extra mileage to Panja in deciphering the old literature. An author of more than 14 books in Ayuurveda, Panja had done his BAMS from Calcutta University in 1997 with three distinctions in Itihas, Agad and Charak and later obtained his MD in Ayurveda Samhita from Rajasthan Ayurveda University in 2003. He was also awarded Phd by Dr Sarvepalli Radhakrishnan Rajasthan Ayurved University in 2008.Panja has a sound knowledge and understanding in all components of Ayurveda, commencing from his command over Sanskrit language to interpreting manuscripts and flourishing clinical practice. “Bengal has contributed about 80 percent literature research in the form of commentaries of classical texts in Ayurveda, over a period of 1,300 years,” Dr Panja said.Ends.last_img read more

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