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Researchers Suggest Quantum Dots as Media for Teleportation

first_img 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. Quantum teleportation performed with light from a quantum dot embedded in an LED Here, researchers focus on semiconductor quantum dots containing as few as a thousand atoms of a semiconducting element, such as silicon, and having diameters as small as one nanometer. They are often referred to as “artificial atoms” because their behavior can be quite similar to a single atom. For example, a semiconductor quantum dot’s electrons can be confined in a way similar to how a single atom’s electrons are bound. Therefore, a quantum dot can be described by a single quantum state, despite consisting of hundreds or thousands of atoms.Researchers Leong Chuan Kwek and K.W. Choo of Nanyang Technological University in Singapore modeled a teleportation system consisting of two quantum dots. They first investigated how the fidelity of the teleportation process would be affected by quantum “entanglement” – when two or more quantum states have to be described with reference to each other, even when spatially separated. The model revealed that the entanglement of the dots is proportional to the fidelity: as one increases, the other increases. Kwek and Choo then developed general equations that would yield a suitable magnetic field, dot-to-dot distance, and temperature (which would all depend on the size of the dots and other variables) such that the fidelity of the system would be better than the average fidelity of non-quantum communications.“Our work provides some preliminary estimates on the way self-assembled quantum dots might be fabricated in terms of inter-dot distances for experiments at room temperature,” Kwek told PhysOrg.com.He and Choo also studied how the system would handle “decoherence,” the often unavoidable interaction of a quantum system with its environment, which compromises the transfer process. Decoherence is one major issue facing quantum computing. Two decoherence models show, however, that the quantum-dot system could still function under a moderate amount of decoherence.Finally, the researchers used the model to study a quantum-state transfer or swapping of states between two quantum dots, an ability necessary for quantum information processing. They determined that a “perfect” transfer is possible using a quantum-dot teleportation system, meaning that the transferred quantum state is exactly the same as the initial quantum state of the first dot.Citation: K.W. Choo and L. C. Kwek, “Quantum dot as a resource for teleportation and state swapping.” Phys. Rev. B 75 205321 (2007)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. Citation: Researchers Suggest Quantum Dots as Media for Teleportation (2007, June 21) retrieved 18 August 2019 from https://phys.org/news/2007-06-quantum-dots-media-teleportation.htmlcenter_img According to recent research, tiny clusters of atoms known as quantum dots may be excellent media for quantum teleportation, a physics phenomenon in which information – in the form of a quantum state, a very specific mathematical “signature” of an atom – can be transmitted almost instantaneously to a distant location without having to physically travel through space. Teleportation is one facet of quantum information science, a developing field that could have a major impact on computing and communications. Explore furtherlast_img read more

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Researchers refute idea that Neanderthals drove mammoths over cliff in Jersey

first_img Today, Jersey is a British Crown dependency—an island off the coast of Normandy. But 200,000 years ago, ocean levels were lower—so low that parts of the site, now known as LaCotte de St Brelade were above the water line. To get a better handle on how the mass of bones wound up at the sight, the researchers obtained a survey of the seabed as it stretches away from the cliff. In analyzing the terrain, the researchers noted that in order for mammoths or other beasts to be driven over the cliff, they would have first had to have been driven down into a dip, then back up again before arriving at the edge of the cliff—the terrain itself would have been very rocky as well, suggesting that a herd of mammoths would have dispersed long before reaching the cliff, and thus could not have all plunged to their deaths together.The researchers also noted that some of the excavated bones near the bottom of the pile showed signs of being burnt, which suggests the bones were used by the Neanderthals after death. The researchers contend that rather than driving the mammoths over the cliff en masse, they instead hunted them individually and carried their bones to the site where they were found—to eat the meat off them, and to use the bones for burning or other purposes. Many other Neanderthal artifacts have been found at the site, suggesting it’s a place where they lived on and off for many years, before finally moving away as the climate grew too cold for them. Journal information: Antiquity © 2014 Phys.org Explore further Ancient giant sloth bones suggest humans were in Americas far earlier than thought More information: A new view from La Cotte de St Brelade, Jersey, Antiquity, antiquity.ac.uk/ant/088/ant0880013.htmAbstractDid Neanderthal hunters drive mammoth herds over cliffs in mass kills? Excavations at La Cotte de St Brelade in the 1960s and 1970s uncovered heaps of mammoth bones, interpreted as evidence of intentional hunting drives. New study of this Middle Palaeolithic coastal site, however, indicates a very different landscape to the featureless coastal plain that was previously envisaged. Reconsideration of the bone heaps themselves further undermines the ‘mass kill’ hypothesis, suggesting that these were simply the final accumulations of bone at the site, undisturbed and preserved in situ when the return to a cold climate blanketed them in wind-blown loess.center_img The Reconstruction of the Funeral of Homo neanderthalensis. Captured in the Hannover Zoo. (Via Wikipedia) (Phys.org) —For half a century, archaeologists have been puzzling over a mass of woolly rhino and mammoth bones found at the base of a cliff on the island of Jersey in the English Channel—most have assumed they were the result of a mass execution by Neanderthals driving them over the cliff. Now a new team of British researchers has found evidence to suggest the bones were carried there instead. In their paper published in the journal Antiquity, the researchers claim their investigation shows that it would have been nearly impossible for Neanderthals to drive them to the cliff, much less get them to run off of it. Citation: Researchers refute idea that Neanderthals drove mammoths over cliff in Jersey (2014, March 4) retrieved 18 August 2019 from https://phys.org/news/2014-03-refute-idea-neanderthals-drove-mammoths.html 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.last_img read more

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Researchers find a way to improve FELs approach used to study Photosystem

center_img Journal information: Nature A team of researchers in Japan has developed a technique for improving the free electron lasers (FELs) approach to studying Photosystem II that allows for creating high-resolution images of the oxygen evolving complex (OEC) in plants. In their paper published in the journal Nature, the team describes their new technique and how their work might lead to a better understanding of the entire photosynthesis process. Ilme Schlichting, of the Max Planck Institute offers a News & Views piece on the work done by the team in the same journal issue. New technique facilitates analysis of biomolecules in a near-natural state Explore furtherlast_img

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Modi lashes out at disruptive Cong hails Mulayam

first_imgAddressing public rallies in Rishikesh (Uttarakhand), Saharanpur (UP) and at a function in Chandigarh, Modi said he had decided to share his feelings before the public because ‘Jan Sabha’ (public assembly) is above the Lok Sabha where the government’s voice was being “throttled” despite being given a massive mandate by the people. Hitting out at the Congress over repeated deadlock in Parliament, Modi said 40 MPs were “conspiring” to hamper the country’s development against the wishes of 400 MPs which was an “insult” to democracy. Also Read – Punjab on alert after release of excess water from Bhakra dam“Beyond the Lok Sabha is ‘Jan Sabha’ and that is why I am expressing my views here. Some people (opposition) are doing this just for their arrogance. There can be nothing more unfortunate than this. The people will not forgive these parties for their conduct in Parliament,” he said.  In the same vein, he appreciated Samajwadi Party leader and Uttar Pradesh strongman Mulayam Singh Yadav for making attempts to break the logjam in Parliament during the Monsoon session, which was washed out. “He (Mulayam Singh) may be our political rival but he does not practice negative politics,” said Modi, while launching a blistering attack on the Congress saying, “Opposing the government’s policies and dissenting with it is okay but doing negative politics is not good for democracy. The Congress must understand the difference between the two and learn to respect people’s verdict.” Also Read – Union Min doubts ‘vote count’ in Bareilly, seeks probe“40 MPs are conspiring to block development of the country against the wishes of the 400 MPs. Time has come to spread awareness about democracy in the country and for the people to pressurise their representatives to do their work in Parliament by asking questions and debating issues and letting the Houses function,” he said.Noting that the region sends large number of people to the armed forces, Modi said his government delivered on its promise of implementing “One Rank, One Pension (OROP).” He said his government tried to honour the soldiers by fulfilling their demand for One Rank, One Pension. The Prime Minister said no previous government paid adequate attention to the enormity of the exercise and attacked the previous UPA dispensation, saying if it had thought about it then it would not have allotted only Rs 500 crore. The armed forces veterans should thank the poor people of the country for implementing OROP which entails a whopping Rs 10,000 crore expenditure per annum, he said. He said, “We also thought that perhaps the expenditure on OROP will be a bit more than Rs 500 crore.”last_img read more

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Celebrating IndiaChina Tourism Year

first_imgTo celebrate the Visit China Year in India 2016, China National Tourism Administration (CNTA) will organise Chinese OPERA Show, the classic milestone-style opera, which will showcase ‘Goddess Marriage – An unbelievable Love Story from China,’ on January 14 at Sirifort Auditorium. The event will be programmed by Anhui Huangmei Opera Theatre, China. The main aim of this cultural evening is to present a slice of Chinese culture to the Opera lovers in India, and to encourage Indian tourists to visit China. Huangmei Opera has grown into a famous opera enjoying a good reputation from folk drama. It mainly narrates a beautiful love story between immortal and mortal.   Also Read – ‘Playing Jojo was emotionally exhausting’Act 1 will showcase “The Magpie Bridge”- Rules are heavy and time is dreary in heaven, where the seven fairies came to the magpie bridge to have a peep on mortal word while their father, the Jade Emperor was busy. Act 2 will showcase “Encounter”- The scene in mortal world is like a profusion of color, where the seventh fairy didn’t know how to tell Dong Yong about her deep love. Dong Yong refused her request of marrying him by various reasons, however, the seventh fairy had already made up her mind to marry him, and she used the white fan to make the pagoda tree talk, and finally they got married. Also Read – Leslie doing new comedy special with NetflixAct 3 will showcase “Serving Bond”- The seventh fairy went together with Dong Yong to Squire Fu’s home. Squire Fu didn’t want to adopt the seventh fairy, but had no reasons to refuse, so he said that he can’t support the seventh fairy until she weaves ten bolts of brocade in one night. Act 4 will showcase “Spinning Silk”- Silk like this surely can’t be weaved into brocade, let alone finishing the weaving in one night but the seventh fairy recalled the incense her eldest sister gave her while leaving the heaven. Seventh Fairy lit the incense and the smoke rose into the heaven which made her sisters come and help the seventh fairy in the weaving room, where they united with happy laughter and cheerful voices and finally finished the weaving of ten bolts of brocade before dawn. Act 5 will showcase “Separation”- The three-year contract is finally shortened to a hundred days, and they went back home after fulfilling the hundred-day bond. However, the Jade Emperor made an edict to arrest the seventh fairy who obeyed the rule back to Heaven while they were enjoying their conjugal love and happiness and dreaming of beautiful life in the future. While the deadline of going back to heaven was coming, the seventh fairy had to leave with teary eyes. At farewell, the seventh fairy told Dong Yong, “Heaven rule may separate us, but you and I will always be one” and also made an oath- “When spring arrives next year, I’ll hand you our son under the pagoda tree”.With the arrival of Spring, the seventh fairy borne by the promise she made to Dong Yong in mind, went back to the mortal world again, and gave their baby to Dong Yong under the pagoda tree. Anhui Huangmei Opera Theatre is one of the most popular theatre groups from Anhui, Jiangxi, Hubei and some other provinces in China.When: January 14 Where: Sirifort Auditorium 1, Khel Gaon Road Timings: 7 pmlast_img read more

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NGMAs Nandlal treasures at Venice Biennale

first_imgDirector General of NGMA Adwaita Gadanayak is upbeat about India’s participation at the Venice Biennale. Along with the ministry of Culture, National Gallery Of Modern Art celebrates 150 years of Gandhi in the exposition of the Haripura Posters created by famed artist Nandlal Bose, belonging to the NGMA’s own collections which are indeed National Treasures .In August 2017, NGMA celebrated 70 years of Independence, by hosting an exhibition to awaken our political consciousness which included the historic Haripura Posters that awakened political consciousness at large. Also Read – Add new books to your shelfNationalist spirit and fervour was the signature of Nandlal’s Haripura posters. They also reflect his acute sensitivity to the landscape and village folk around him. Each poster is a validation of vitality and liveliness for more than 70 years after they were created. “Nandalal and his associates produced around 400 posters for the Congress convention at Haripura, held in February 1938,” reflects the Director General. “These posters were all produced on handmade paper with pigments made from local earth and stones, and mounted on straw boards; none were printed or mass-produced,” he affirms. Also Read – Over 2 hours screen time daily will make your kids impulsiveSharing the history – “To imagine that they were executed in 1937; commissioned by Gandhi for the Indian National Congress Party meeting in 1938, at Haripura – these are benchmarks in Indian history.” Nandalal Bose looked at cultural idioms and the fabric of the common man when he created images of musicians, iron smith, tailors, even a monk creating pottery, an esraj player, a veena player, or just women doing their chores. One of the finest among these posters is the Bull Fighter. In that poster, the vigour and tenacity of the man and bull are shown through strong, gestural lines and swaths of bright, bold colours. Bull Fighter was prominently displayed at the conference grounds at Haripura. Deceptively simple in appearance and invoking flavour of folk painting the Haripura Posters are amalgamation of the decorative and the calligraphic art with a rare ingenuity as well as personal insignia. “At the Venice Biennale we will display them as independent works of art but history says they were done in order to decorate a temporary township built for the annual session of the Indian National Congress in the remote village of Haripura in early 1938,” adds Gadanayak. According to historical notes by art historian R Siva Kumar, the township was built of local materials and in harmony with the rural surroundings. The decorations were conceived, both in style and idiom, following the same aesthetics and were designed to complement the temporary structures. Sivakumar wrote in an essay that they have to be imagined in their original context as part of a broader design to be fully appreciated. The posters also evoke Gandhian ethics and creativity. Gadanayak as Commissioner of India Pavilion, is proud to be part of the Venice Biennale 2019, one of the finest expositions in the world of contemporary and avant garde art.last_img read more

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