Quantum computing Entanglement may not be necessary

first_img(PhysOrg.com) — It is a truth universally acknowledged that quantum computing must have entanglement. Measuring light and vacuum fluctuations from a time flow perspective “Entanglement,” Andrew White tells PhysOrg.com, “is normally considered a non-negotiable part of quantum information processing. In fact, if you told me a couple of years ago that you could do quantum computing without entanglement, I would have been pretty skeptical – to say the least!” White says that he first heard the idea of non-entanglement quantum computing from Carl Caves. “I was intrigued when Professor Caves, on sabbatical here in Australia from New Mexico, mentioned that there were sober predictions that entanglement wasn’t always necessary.”White leads a team of young experimental scientists at the University of Queensland in Brisbane, Australia. Ben Lanyon, Marco Barbieri, Marcelo Almeida and White have been studying deterministic quantum computing with only one pure qubit (DQC1). “Entanglement is not the final story on what makes quantum information processing powerful,” White insists. The Australian team’s results can be found in Physical Review Letters: “Experimental Quantum Computing without Entanglement.”“Normally, in order for quantum computing to work,” White explains, “we need to encode the information into quantum bits—qubits—which are in a noise-free pure state. It’s known that the entanglement between these is what makes standard quantum computing powerful.” He continues, “With a DQC1 scheme, you only have to have one pure qubit, and the rest can be noisy or mixed.” The idea behind quantum information processing using entanglement is that noiselessness has to be applied in order to provide a substantial advantage over classical computing. DQC1, though, could potentially offer a more efficient and less resource-intensive method of quantum computing, since entanglement would no longer be a necessity.“For this demonstration,” White says, “we used the smallest possible example: a circuit with just two qubits, one pure and one mixed. We ran a phase-estimation algorithm as a small example, and found in every setting there was zero entanglement, but that most of the states couldn’t be described efficiently in a classical manner.”White points out that this is suggestive that there are other possibilities, beyond entanglement, that contribute to the power provided by quantum information processing. “We’re still chewing through the implications,” he says. “This is not a universal panacea,” White admits. “For some problems and algorithms you just need pure qubits and entanglement, problems such as Shor’s algorithm. However, there are applications and problems where the DQC1 method will work quite well, and will be more efficient than trying to get qubits that are all pure.”With so many different architectures and schemes for quantum computing – all of them trying to create a system in which all the qubits are pure – it is rare to see a group looking to find applications for a quantum information system that makes allowances for impurity and the introduction of noise – insisting that entanglement is not necessary. “The fact is that certain classes of problems don’t need entanglement, and they don’t need all of the purity. In some cases, all that is needed is one pure qubit and the rest could be mixed. Really, with DQC1, you don’t have to work as hard as you think you do.”We are starting to build more complicated algorithms to get an idea of where this could go. Regardless, the idea that entanglement may not be necessary for some types of quantum computing is big news.”More information: B. P. Lanyon, M. Barbieri, M. P. Almeida, and A. G. White. “Experimental Quantum Computing without Entanglement.” Physical Review Letters (2008). Available online: link.aps.org/abstract/PRL/v101/e200501 . 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: Quantum computing: Entanglement may not be necessary (2008, December 5) retrieved 18 August 2019 from https://phys.org/news/2008-12-quantum-entanglement.htmlcenter_img 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.last_img read more

Semiconducting nanonetwork could form the backbone of transparent flexible electronics

first_img 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. The researchers, led by Kwanghee Lee, a professor at the Gwangju Institute of Science and Technology in South Korea, have published a paper on the new material in the Proceedings of the National Academy of Sciences. “So far, there has been no semiconducting material that simultaneously achieves excellent optical transparency, high charge-carrier mobility, and real flexibility,” coauthor Kilho Yu at the Gwangju Institute of Science and Technology told Phys.org. “Metal oxides, such as ZnO and IGZO, have excellent transparency and high mobility, but they are brittle and show poor mobility if not treated with high-temperature (>200 °C) processes, which are not desirable for fabrication on flexible substrates. General semiconducting polymers are flexible, but show poor mobility without complex processes and are not very transparent because of their high optical absorption coefficient.”The new polymer blend consists of about 15% semiconducting polymer called DPP2T integrated into an inert polystyrene matrix. The two types of polymers do not mix uniformly, but instead the DPP2T forms a web-like nanonetwork through the inert matrix, creating highly ordered, continuously connected charge pathways for rapid charge transport. So far, transparency has been particularly challenging to achieve in semiconducting polymers because of their inherently high light absorption in the visible range. DPP2T belongs to a newer class of semiconducting polymers in which the light absorption peak is red-shifted to the near-infrared range, so it absorbs much less light in the visible range and has greater optical transparency. However, DPP2T by itself still has a greenish tint. Only by blending the DPP2T with the polystyrene matrix could the researchers fabricate a material that is almost perfectly transparent throughout the visible range.In the final analysis, the researchers showed that the individual materials in the polymer blend cannot achieve all three of the desired properties on their own, but only when blended together. © 2017 Phys.org Field-effect transistors integrated with LEDs, showing transparency and flexibility. Credit: Yu et al. ©2016 PNAS Graphene produces more efficient transport of a semiconducting polymer film Photograph of the flexible, transparent field-effect transistor made of the new material. Credit: Yu et al. ©2016 PNAS Citation: Semiconducting nanonetwork could form the backbone of transparent, flexible electronics (2017, January 13) retrieved 18 August 2019 from https://phys.org/news/2017-01-semiconducting-nanonetwork-backbone-transparent-flexible.html More information: Kilho Yu et al. “Optically transparent semiconducting polymer nanonetwork for flexible and transparent electronics.” Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1606947113 To demonstrate, the researchers fabricated prototypes of colorless, bendable field-effect transistors integrated on top of colorless, bendable light-emitting diodes. The devices could withstand 1,000 bending cycles with no severe performance degradation. (Phys.org)—Researchers may have found a “sweet spot” for organic electronics by fabricating a new 2D semiconducting polymer-blended nanonetwork material that simultaneously achieves excellent charge mobility, high flexibility, and nearly 100% optical transparency—a combination of properties that has so far been elusive for semiconducting materials. According to the researchers, the nanonetwork is the first truly colorless, bendable semiconducting material, as demonstrated by the fabrication of field-effect transistors with integrated LEDs. “The nanonetwork semiconductor can be made very easily and is solution-processable, and it needs no heat treatment or any other complex processes,” Yu said. “It simultaneously achieves excellent characteristics for future transparent, deformable electronic applications. The applicability of the nanonetwork semiconductor was proven by the fabrication drive of prototype FET/OLED integrated devices. In the paper, we also have shown a new paradigm for achieving facile charge transport in semiconducting polymers, which emphasizes the importance of clean charge pathways along the polymer backbone, rather than the degree of crystallinity of the polymer.”The researchers expect that the results will pave the way for the development of a wide variety of applications, such as next-generation “see-through” bendable electronics and skin-attachable medical devices.”We are currently investigating the intriguing charge transport mechanism of the nanonetwork semiconductor using various experimental tools and modeling,” Yu said. “In addition, we are applying this nanonetwork semiconductor toward various electronic applications, in order to make it a platform technology for deformable and transparent electronics.” Journal information: Proceedings of the National Academy of Scienceslast_img read more

From the streets on to the stage

first_imgSounds like a scene out of any perfect Hollywood movie, but that  is exactly where some lucky kids are headed. A lucky break like the one provided by Aanukrati could go a long way to change their lives. These street kids would unite with young contemporary dancers for Anurakti. An initiative that drives to surpass the socio-economic divide and create a mutual understanding between different strata’s through dance. Anurakti is a team of young contemporary dance artists who would be seen tapping their feet with the brilliant self trained acrobatic talents from the street.  Anurakti dabbles into various dance techniques featuring mayurbhanj chhau, lyrical jazz, Kathak and street acrobatics. Also Read – ‘Playing Jojo was emotionally exhausting’The idea behind it is to put the gymnastic talents of these street children at its best use in an attempt to change to course of their life through the guidance of a dance company.  What drives the Urshilla Dance Company team forward: It is rooted in a scene at the traffic red lights, something all of us witness and ignore- the spread out arms of little kids on the road. UDC aims to make these little hopeful arms stretch out not for alms but a heartfelt embrace. Also Read – Leslie doing new comedy special with NetflixWith the thought of imparting a sense of pride and a sense of belief in them, UDC hand picked these young artists from the streets of Delhi and created a piece with their team of trained dancers.Enthusing a sense of confidence, UDC would bring forth the talent of these kids through a piece that explores contemporary dance with new dimensions of lighting and multimedia. It would take you through an emotional journey of two street kids with a twinkle in their eye to become famous dance artists and how a dance company makes turns their aspirations into reality.The show has a mass appeal owing to its entertaining story telling; though it is abstract in its form.  UDC is currently nurturing the talents of six street children who would all be performing in this show. DETAILAt: Kamani AuditoriumOn Till: 19 April, 7 pmlast_img read more

Life is Football

first_imgThis week has been so terribly busy that I’ve literally had no time to breathe. Well, almost. It’s been raining intermittently in Calcutta, and all the associated paraphernalia – lethargy, love, longing and such- are taking over our senses slowly and gradually. To be working indoors while fresh rains are making sweet love to the parched earth outside feels criminal. I, for one, have to constantly fight the urge to rush out every time the rains come calling, and splash around with gay abandon. Maybe, sing a line or two, too. But as they say, such things happen only in dreams. Or, in the movies. Now, I’m pretty sure the latter will never happen to me, but who’s to stop me from dreaming? So, this past week I’ve mostly been in the studio writing songs, while imagining that I’m holding hands with the perfect man, singing the 1969 classic Raindrops Keep Falling On My Head from the Paul Newman and Robert Redford (perfect men!) starrer Butch Cassidy and the Sundance Kid, and getting drenched in some heavenly elixir!   Also Read – ‘Playing Jojo was emotionally exhausting’This is the story on most days, but nights bring with them a different hazard altogether- football. I’m Bengali. Our love for football is a part of our DNA. I just read a joke that’s been doing the rounds on social media sites- Indians getting excited about the football World Cup is like Brazilians getting excited about Diwali. Well,  a) it’s ridiculous to compare an annual, regional, religious festival with a quadrennial, international, sporting extravaganza that gives joy to everybody who watches. b) There’s no difference between Bengalis and Brazilians when it comes to our love for the game. Don’t believe me? Ask Pele. He’s played in Calcutta in front of maddening crowds! So, jokes such as the one I mentioned don’t apply to my fellow bong brethren.  Also Read – Leslie doing new comedy special with NetflixAnd, like a true-blue Bengali, I’ve been religiously following every match. Of course, the Dutch proved that revenge is a dish best served (mercilessly) cold when they annihilated defending champions (and, one of my favorites) Spain last Friday, and that crushed me to such an extent that I continued to weep bitterly long after the match was over. But, that did nothing to break my indomitable spirit, and Pirlo’s magical skills during Italy’s convincing win over the valiant English made sure I stayed hooked. It’s been a week of fantastic, unpredictable football (and, very little sleep), what with underdogs turning the tables, and lions turning into mice, but one can’t say the same about the theme songs this year. Jennifer Lopez and Pitbull’s insipid anthem We Are One has not found many takers, and WAG Shakira’s uninspired Dare You failed miserably in creating Waka Waka (Shakira’s 2010 anthem) Part 2.  But, what has caught our eyeballs (and, looks poised to take the world by storm) is our very own disco-king Bappi Lahiri’s offering Life Is Football. After capturing our hearts and imagination with his tribute to Michael Jackson (King Of Pop Don’t Say Goodbye), Bappi Da has now come up with a befitting reply to JLo-Pitbull-Shakira. Don’t believe me? Please go look it up on Youtube! You can thank me later. And, here are the words, so we can sing along to Bappi da ka mewjik!Who-ee aar all one/Dreams aar haaaai/Threeell and faaan…that’s football!/Rheethem ees football/Speed ees football/Akshun ees football/And thee whole waarrld laavs football/O ole ole/Ole ole o/Oooway oo. Bappi da, take a bow. Jlo & Co., baaju hato!Malini Banerjee is a snotty single child, mountain junkie, playback singer, Austen addict, hopes to soon finish writing her debut novel, and dreams of singing alongside Buddy Guy.last_img read more

HC to hear plea against proposed MCD strike

first_imgThe Delhi high court on Monday agreed to hear on Tuesday a plea seeking to restrain the civic bodies in the national Capital from going on strike again.The matter was mentioned before a Bench of justices Badar Durrez Ahmed and Sanjeev Sachdeva which directed that it be listed for hearing on Tuesday. The petition was filed by a lawyer who moved the court as an association of MCD unions has again called a strike on July 22 demanding primarily reunification of the three Corporations as well as payment of pending salaries and other arrears. The association also made other demands which include declaration of sanitation workers as technical employees, timely payment of terminal benefits of retired and deceased employees, pension benefits, cashless medical card facility as well as providing houses to them. The petitioner, Sanjeev Kumar Arora, said that proposed strike of July 22 “is of much wider consequence” as it has been called by all the employees of the Municipal Corporations of Delhi and thus it will “jeopardise the health, safety and normal life of the people” of the city.last_img read more

Kolkata Police initiates drive to spread awareness on ATM fraud

first_imgKolkata: Besides carrying out a probe to arrest the people behind the case of ATM fraud, Kolkata Police has initiated a drive to makecommon people aware of information regarding the crime to avoid such incidents in future.Kolkata Police has taken several initiatives to make people aware of the same, which includes sharing messages and videos on social networking sites.According to a senior police officer, the stress has been given on campaigning on social media, as mostly youngsters use the online mode of monetary transaction. Also Read – Rain batters Kolkata, cripples normal lifeThe Bank Fraud section of Kolkata Police’s Detective Department has prepared a video and uploaded it on its Facebook page on Friday, with detailed information on what a person should do to avoid falling prey to such crimes.It may be mentioned that recently, around 80 complaints were lodged with the police, alleging unauthorised withdrawal of money from various bank accounts. Investigation has revealed that money from ATM counters was withdrawn after cloning debit cards of several different bank account holders. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedThe police have advised not to use unmanned ATM counters. At the same time, a user also needs to ensure that only one person remains inside an ATM counter at a time and details of debit cards should not be shared with anyone.Moreover, one should not seek help of any unknown person while using an ATM.Most importantly, the police have also advised people to be alert while swiping debit cards in an ATM machine and keying in the password for a transaction. One must not leave an ATM counter immediately if the machine gets disabled during an ongoing transaction.The police have also urged people to be alert while making online payment and one should prefer the use of personal computers for the same. In case of any trouble, people can also seek help of the police on their helpline number 8585063104.last_img read more

KMC issues notice to 52 old dangerous buildings

first_imgKolkata: The Kolkata Municipal Corporation (KMC) has already issued notices to 52 old and dangerous buildings in the city under the amended Building Laws, Section 412A of KMC Act, 1980. The hearing is in final stages for 13 such buildings, Mayor Sovan Chatterjee said during the monthly meeting of the civic body on Tuesday.It may be mentioned that the amendment empowers the civic body to acquire old buildings whose owners refuse to repair them.The civic body will give notices to the owners and in case they are tenanted structures, will ask them to sit with the tenants and get them repaired at their own expense. Also Read – Rain batters Kolkata, cripples normal life”In as many as 212 cases, we have already got the approval of the Municipal Building Committee (MBC) to slap notices under the amended Section 412A of KMC Act, 1980,” Chatterjee said, answering a query from Left councillor Debasish Mukherjee, on the implementation of the amended building rules.Chatterjee further maintained that the maximum number of notices have been slapped at Borough 4, which includes 37 old and dangerous buildings. Borough 2 comes second in the list, with notices served to 10 buildings, while the number of notices served in Boroughs 6, 7, 8 and 12 are 4, 1, 1 and 1 respectively. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedThe building department is yet to serve notices in boroughs 1, 3, 9, 10, 11, 12, 14, 15 and 16.The civic body has already demolished some buildings in the city, particularly in Central Kolkata, since the month of July.A drive for pulling down a building at 80 Bentinck Street was undertaken on Tuesday. It may be mentioned that when a KMC team had gone for demolition of the building in the morning, they were prevented from doing so and the occupants claimed that they would take up repair work on their own, in consultation with the owner. However, even after late afternoon, there was no trace of the building owner. “The building was posing a major risk to a number of businessmen who were occupying the ground floor and also the pedestrians walking on the footpath. So, we have began the work for pulling it down,” an official of the building department said.In the year 2017, 22 people had died after portions of old buildings fell on them. In 2018 too, there have been some deaths due to building collapses.last_img read more

Plastic water bottles up the risk of obesity in kids

first_imgBisphenol A (BPA) is one of the most widely used chemicals in products of everyday use like plastic water bottles, metal food cans and thermal receipt paper. The findings showed that mothers who exposed their foetus to BPA increased their risk of developing a high fat mass index –a measure of body fat mass adjusted for height, per cent body fat, and waist circumference – by the age of seven. A whopping 94 percent of women in the study had the chemical in their urine and their school-aged children showed increased measures of body fat. Also Read – ‘Playing Jojo was emotionally exhausting’Also, children exposed to higher concentrations of prenatal BPA had higher levels of adiposity. BPA, which is also one of the endocrine disrupting chemicals may alter the baby’s metabolism and lead to an early formation of fat cells in their body, the researchers said.“The study provides evidence that prenatal exposure to BPA may contribute to developmental origins of obesity as determined by measures of body fat in children as opposed to the traditional indicator of body mass index, which only considers height and weight,” said lead author Lori Hoepner from Columbia University in the US. Further, the association between BPA and fat mass index and waist circumference was higher in girls, the researchers said. Also Read – Leslie doing new comedy special with NetflixHowever, there was no association found between prenatal BPA exposure and body fat outcomes in boys, the researchers noted in the paper published online in the journal Environmental Health Perspectives.In addition, the chemical has also been linked to several health outcomes such as asthma, attention-deficit hyperactivity disorder (ADHD), anxiety, depression, early puberty in girls, diabetes, obesity and heart disease in adults. “The evidence that prenatal BPA exposure is associated with measures of obesity in children may be an important underlying factor in the obesity epidemic,” said one of the researchers, Andrew Rundle, associate professor at Columbia University’s Mailman School of Public Health.For the study, the team analysed urine samples and child body composition from 369 mother-child pairs, from pregnancy through early childhood. Height and weight were measured for children at age five and age seven.last_img read more

Suicide attempt in Kolkata Metro

first_imgKolkata: A young man attempted suicide by jumping in front of a Metro train here on Wednesday, causing brief disruption to Metro services, an official said. The youth was rushed to the R.G. Kar Medical College and Hospital for treatment. “There has been a suicide attempt in Dumdum station,” Kolkata Metro said. The Metro service was partially disrupted between Dumdum and Girish Park stations for nearly 40 minutes.last_img

JU VC promises stringent action against prof who likened womans virginity to

first_imgKolkata: Slamming Prof Kanak Sarkar’s misogynist statement, Jadavpur University Vice-Chancellor Suranjan Das said on Wednesday it has sullied the image of the institution and “stringent” action would be taken against him. Sarkar, a professor of International Relations department, had likened a virgin woman to a “sealed bottle” or “packet” in a Facebook post on Sunday, triggering an outrage. Though he had deleted the post, screenshots of it went viral. Also Read – 3 injured, flight, train services hit as rains lash Bengal “He is a teacher. His comment has sullied the image of the university. It will also take stringent action against him as per rules,” Das said, adding he had also “heard” that he had had made certain objectionable comments in the class in the past. It has to be seen what kind of step could be taken against him as the statement was made on Facebook, the vice-chancellor said. Das said he has come to know that both the National Commission for Women (NCW) and the West Bengal Commission for Women have taken suo motu cognisance of the statement of Sarkar. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killed The NCW on Tuesday tweeted that it has written to the state Director General of Police Virendra to investigate the matter and take appropriate action. An NCW team would also meet the vice-chancellor on this issue this week. Das said the West Bengal Commission for Women (WBCW) has sought an explanation from Sarkar. “He (Sarkar) has been asked an explanation (by the WBCW). We also received its letter,” Das told reporters on the sidelines of the convocation of St Xavier’s College here. The students had boycotted Sarkar’s classes on Tuesday. Asked if he would ask the students to get back to his class, the vice-chancellor said he would not. Student unions of the university on Tuesday submitted memoranda to Das, demanding strict action against the professor. “They (students) can come and meet me. It will be seen what can be done. I also heard that he had had made certain (objectionable) comments in the class in the past,” he said. Sarkar, in his post, wrote: “Are you willing to buy a broken seal while purchasing a bottle of cold drink or a packet of biscuits? It is the same case with your wife. “A girl is biologically sealed from birth until it is opened. A virgin girl means many things accompanied as values, culture, sexual hygiene. To most boys, virgin wife is like angel.” Facing criticism, a defiant Sarkar appeared to justify his comments, asserting that it was intended for “fun” among a social media group of friends and “not for public consumption”. “Someone took a screenshot of the post and forwarded it, which triggered the response. I did not intend to hurt anyone’s sentiment or insult any woman,” he said. He also said according to a Supreme Court order every individual is entitled to express his opinion.last_img read more