Citation: 143 is largest number yet to be factored by a quantum algorithm (2012, April 11) retrieved 18 August 2019 from https://phys.org/news/2012-04-largest-factored-quantum-algorithm.html More information: Nanyang Xu, et al. “Quantum Factorization of 143 on a Dipolar-Coupling Nuclear Magnetic Resonance System.” PRL 108, 130501 (2012). DOI: 10.1103/PhysRevLett.108.130501 (Phys.org) — While factoring an integer is a simple problem when the integer is small, the complexity of factorization greatly increases as the integer increases. When the integer grows to more than 100,000 or so digits, the problem reaches a point at which it becomes too complex to solve using classical computing methods. But quantum computers, with their use of entanglement and superposition, can theoretically factor a number of any size. However, the largest number that has been factored on a quantum processor so far is 21. Now in a new study, physicists have set a new record for quantum factorization by developing the first quantum algorithm that can factor a three-digit integer, 143, into its prime factors, 11 and 13. The physicists, Nanyang Xu at the University of Science and Technology of China in Hefei, China, have published their study on the new quantum computation algorithm in a recent issue of Physical Review Letters. They explain that, despite the potential for factoring any size number, quantum algorithms still face fundamental challenges.“Quantum algorithms can theoretically solve the factoring problem; however, it is still challenging for today’s technologies to control a lot of qubits for a long enough time to factor a larger number,” Xu told Phys.org. “The environmental noises and other imperfections make the quantum system so fragile that decoherence could destroy everything stored in qubits in a short time.”As the physicists note in their study, the first and most well-known quantum algorithm for factorization is Shor’s algorithm, which was developed by mathematician Peter Shor in 1994. This algorithm, which involves quantum entanglement, is based on a circuit model in which a sequence of operations is performed to solve the problem. In the current study, Xu and coauthors use an alternative to Shor’s algorithm called adiabatic quantum computation (AQC). Proposed by Edward Farhi, et al., in 2001, AQC was developed for optimization problems, in which the best value of many possible values is sought. Several computational problems, including factoring, have been formulated as optimization problems and then solved using AQC. Here, the scientists’ algorithm builds on one of these formulations by Peng, et al., in 2008, which used AQC to factor the largest number before now, 21.Unlike Shor’s algorithm, AQC does not run through a sequence of operations, but instead relies on quantum adiabatic processes. More specifically, the algorithm finds a mathematical function called the Hamiltonian in which all possible solutions are encoded as eigenstates, and the correct solution is encoded as the ground state. To solve a problem, the algorithm gradually evolves the Hamiltonian according to a mathematical equation, resulting in the system reaching its ground state and providing the correct answer. (In its physical implementation, the system consists of a liquid-crystal nuclear magnetic resonance (NMR) system like those used in magnetic resonance imaging (MRI), in which magnetic nuclei absorb and re-emit radiation at a specific frequency.) While the adiabatic-based strategy works well in theory, in reality it still faces challenges when factoring large numbers because the Hamiltonian’s spectrum of all possible eigenstates grows exponentially with the size of the integer. So Xu and coauthors developed a way to suppress the spectrum’s growth by simplifying the mathematical equations governing the Hamiltonian. In the end, the physicists’ simplified equations significantly decreased the growth rate of the spectrum to make it easier to factor larger numbers than before.“We use a new method and reduce the qubits needed in the algorithm, which finally made the factorization of 143 available in realization,” Xu said. “Our work shows the practical importance of the adiabatic quantum algorithm.”In the future, the strategies used here could lead to even larger integer factorization by quantum algorithms.“It is possible to factor a larger number using the strategies in our current paper on current quantum computing platforms,” Xu said. “In this issue, we plan to improve our control ability towards the NMR quantum processor to factor a larger number, and the exact time complexity of the algorithm is still an open question.” Physicists Solve Difficult Classical Problem with One Quantum Bit Explore further Quantum factorization of 143 using the adiabatic quantum algorithm. As the system evolves to its ground state k = 6, it reaches a superposition of states 6 and 9, which denotes the answers 11 and 13. Image credit: Xu, et al. ©2012 American Physical Society Copyright 2012 Phys.Org 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. 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.
Month: August 2019
The idea is to sell a slew of the Hiriko EVs to municipalities, who then rent them to commuters, as shared vehicles. A person leaving work could walk to a lot where several of the Hirikos are parked, rent one to drive to the train station, leave it there in a special lot, ride the train home, rent another Hiriko to get home, keep it overnight, then drive it back to the special lot, leave it there and then take the train to work and so on. Thus, those that rent the Hirikos would not rent a specific car, but would get a different one every time. In such a scenario, those that rent would do so by the month or year, to make things easier of course. The advantage to commuters would be an easy way to get to and from work while the advantage to the city would be fewer vehicles clogging streets, less air pollution and more vehicles able to fit into parking lots because of the tiny parking requirements of the Hiriko.To make parking even easier engineers have designed all four tires to turn independently, allowing drivers to slide sideways into spots if necessary. The car would not be for everyone of course as it can only go 31 miles per hour maximum, though it does have a range of 75 miles. The company has already made 20 of the cars which are being tested by various groups. They are currently trying to sell to San Francisco, Berlin and Barcelona, at a price of about $16,000 each. Citation: Spanish group demos “Hiriko” fold-up urban EV (w/ Video) (2012, August 10) retrieved 18 August 2019 from https://phys.org/news/2012-08-spanish-group-demos-hiriko-fold-up.html That initiative has led to a working relationship with a group of auto parts suppliers in the Basque region of Spain, who have formed what they call the Hiriko Driving Mobility Group, whose purpose is to solve congestion and parking problems in downtown city areas. The result is a car concept called the Hiriko, which in Basque, means, “from the city.” It’s an electric vehicle that when driven is about eight feet long, but when parked, can be squeezed or folded down to just five feet, which is shorter than the average bicycle. Explore further (Phys.org) — Ten years ago, MIT’s Media lab began working on a concept for an urban vehicle to replace bicycle sharing, and other options people were using to get them to and from public transportation, to cover that first mile, as it’s known; the distance between where they live and the train station; or the last mile, from the train to where they work. It’s a problem that has become more urgent as congestion in city centers worsens over time as cities become ever more crowded. Fold-up car of the future unveiled at EU © 2012 Phys.org 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.
© 2014 Phys.org Citation: China’s PandaX WIMP detector set to begin operations soon (2014, January 31) retrieved 18 August 2019 from https://phys.org/news/2014-01-china-pandax-wimp-detector.html The field cage for phase-1a Super-CDMS researchers report possible evidence of WIMPs The field cage integrated with the top PMT supporting plate 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. Explore further Several facilities around the world are already conducting the same sort of research, of course, but the facility in China has a decided advantage—it’s sheltered beneath tons of marble. As with the other facilities, the idea is to prove that WIMPs are real and by extension, that theories about dark matter are as well.Dark matter isn’t something that has been proven to exist, instead, it’s a theory that has been developed to explain gravitational anomalies in space—why do galaxies have gravitational effects by objects that cannot be seen? Scientists believe it’s because of a type of matter that has a gravitational impact, but cannot be seen by the naked eye, or with any other type of device that physicists have conceived. The best they’ve been able to come up with is the idea of WIMPS—a theoretical elementary particle that makes up dark matter. If the existence of WIMPS can be proven, that would go a long way towards proving that theories regarding dark matter are true too.Thus far none of the research facilities constructed to detect WIMPs has been able to do so, though the idea for all of them is essentially the same—fill a big tank with a certain type of material, shield it from other space based particles, then watch for collisions between the nucleus of an atom of the material used and some other particle—hopefully, a WIMP. With the Chinese project, the material is xenon—1.2 metric tons of it. Physicists hope that if such a collision does occur, photons and electrons will be given off and the combination of the two will be enough for sensors to detect where in the vat the collision occurred. That will allow for calculating the speed of the object that made its way in, which can be compared with theories about the speed at which WIMPs travel—if the two match, physicists around the globe will conclude that it was most likely a WIMP and those on the project can start preparing their Noble Prize acceptance speeches. More information: pandax.physics.sjtu.edu.cn/ (Phys.org) —China’s PandaX Dark Matter Experiment is in final preparations to begin operating sometime early this year, representatives for the project have told the press. Its mission is to capture evidence of a Weakly Interacting Massive Particle (WIMP) colliding with the nucleus of a xenon atom—evidence of dark matter.
The India trip of American reality TV star Kim Kardashian has reportedly been cancelled over visa issues.‘Unfortunately, Kim will not be able to enter the country due to some visa issue’, said a source. However, the exact reason behind cancellation has not been disclosed. ‘The reason is not clear but all we know is that there was some visa issue which she could not fulfill and the trip has been cancelled,’ the source added. The 34-year-old star, who shot to fame with TV series Keeping Up with the Kardashians, was supposed to come to the country to promote her new fragrance Fleur Fatale.
Kolkata: A Class X student drowned at a pond in the Maidan area on Sunday morning. The deceased teenager Shaad Khan is a resident of Park Street near Mullick Bazar.Police sources said Shaad who had just appeared for his Madhyamik examination had gone to play football with some of his friends on Saturday late afternoon and the ball fell into the pond popularly known as Manohar Das Tarag. They could not find the ball in the water as it had gone dark. Shaad along with his younger brother went to the same spot at around 7 am on Sunday to look for the ball and found it in the middle of the pond. Shaad opened his slippers on the stairs and dived into the water to pick up the ball. Also Read – Heavy rain hits traffic, flightsAfter he picked up the ball and was swimming back to the bank of the pond, something got entangled with his legs and he started struggling in the water. His brother Muzaffar raised an alarm and alerted the morning walkers in the area. However, the teenager drowned in a few minutes before anybody could attempt to save him. An officer of Kolkata Mounted Police who was present in the area informed the Park Street police station. Divers from Kolkata Police’s disaster management group fished out the body following which it was sent for post mortem. Shaad was an NCC cadet and expert in swimming too.”His family members have informed that the victim was an expert in swimming. We are probing what led to his drowning,” a senior police officer said.
Kolkata: West Bengal Chief Minister Mamata Banerjee today condemned the I-T raids at a hospital owned by Swaraj India chief Yogendra Yadav’s sisters at Rewari and alleged that the BJP was using government agencies to silence opposition voices before the general election. She also held the BJP responsible of “open political vendetta”. “2019 elections are coming. #BJP using the agencies to silence Opposition voices and openly doing political vendetta. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killed Strongly condemn the IT raid on @_YogendraYadav Ji’s family,” Banerjee wrote on her Twitter handle this afternoon. The I-T Department had on Wednesday raided multiple premises of a hospital group at Rewari in Haryana, which belongs to Yadav’s sisters and seized cash of around Rs 22 lakh after it was detected that they had allegedly made cash payments to a Nirav Modi firm for purchasing jewellery. Yadav had alleged that the raids were carried out with an intent to “intimidate” and “silence” him as he had launched an agitation for fair crop price for farmers and against liquor shops at Rewari. Yadav, who had started his campaign with a nine-day ‘padyatra’ (march) that ended two days ago, said the place and the timing of the raid was to send a message not just to him but also to the many farmers who are fighting for their rights.
Guinea was on Tuesday declared Ebola free by the WHO two years after the virus’ deadliest-ever outbreak began in the country, killing more than 11,000 people in the west African region. A country is declared free of human-to-human transmission of the Ebola virus after it completes a two 21-day incubation period after the last confirmed case has tested negative a second time. Guinea has successfully crossed the 42-day period and Guinea now enters a 90-day phase of heightened surveillance to ensure that new cases, if any, are quickly detected before they spread to other people. The town of Gueckedou in Guinea was the ground zero for the deadly outbreak of Ebola Virus Disease (EVD) and was the last West African state to break the original chain of transmission which killed 11,300 people in the three states of Liberia, Sierra Leone and Guinea. “This is the first time that all three countries Guinea, Liberia and Sierra Leone have stopped the original chains of transmission that were responsible for starting this devastating outbreak two years ago,” World Health Organization (WHO) Regional Director for Africa Dr Matshidiso Moeti said. EVD which started in late December 2013 spread to seven other countries by land and air travel apart from severely affecting the nearby states of Sierra Leone and Liberia. Sierra Leone was declared free of Ebola in November this year. It saw 3,955 deaths and 14, 122 cases in the last two years. Liberia was declared Ebola-free earlier in September. The deadly disease killed more than 2,500 people in the country and a further 9,000 in Sierra Leone and Liberia. However, new cases through human-to-human transmission as a result of the re-emergence of Ebola virus that had persisted in a previously infected individual came up in late November in Liberia. The West African coastal state saw a total of 4,809 deaths and 10,675 cases (as of December 23) from the outbreak of EVD since 2013. In addition to the original chain of transmission, there have been 10 new small Ebola outbreaks, or ‘flares’, between March and November 2015. “These appear to have been due to the re-emergence of a persistent virus from the survivor population,” states the UN health agency.
Kolkata: State Consumer Disputes Redressal Commission has imposed a fine of Rs 13 lakh on two city-based doctors while a private hospital in the Central Kolkata has been asked to pay Rs two lakh after the Commission found negligence in the treatment of a patient.The complainant, a victim of medical negligence and a resident of Shanti Nagar area of Asansol, lodged a case with the State Consumer Dispute Redressal Commission on May 23, 2013. It was stated that the complainant on August 7 in 2012 visited the hospital and consulted a doctor at the clinic with a problem called “upper abdominal pain with nausea and vomiting”. Also Read – Rain batters Kolkata, cripples normal lifeThe doctor diagnosed the patient with “acute cholecystitis” and the patient was advised for “urgent admission” as revealed from the prescription dated August 7, 2012. After the admission of the patient, an USG of the whole abdomen was done and the “impression” of the said USG report revealed “fatty liver with cholelithiasis”. After such detection “laparoscopic cholecystectomy” was done under general anesthesia by another doctor as revealed from the “Discharge Summary and Certificate” dated August 16, 2012. Despite ‘laparoscopic cholecystectomy’ the patient continued to feel the pain in the abdomen. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedShe later visited a private hospital in Chennai that advised ‘C.T. Scan of whole abdomen’ the “impression” of the report dated 17.11.2012 of which revealed “remnant of Gall Bladder with Calculi”. Also, the “USG report of whole abdomen” dated 21.11.2012 in the hospital reported “gall bladder is contracted and shows calculus measuring 1-2 cms within the lumen” and “post partial cholecystectomy — gall bladder calculus with chronic cholecystitis”. Thereafter, the complainant again visited another city hospital where “USG of upper abdomen” was advised and the USG report stated “cystic structure with calculus within it — gall bladder remnant (following partial cholecystectomy) dilated cystic duct stump with stone in it”. After such reports, the complainant revisited the Chennai hospital where “calculus cholecystitis following incomplete cholecystectomy” was diagnosed and “completion Laparoscopic cholecystectomy” was done on 12.12.2012 as evident from the ‘Discharge Summary’ of the said hospital. It is alleged in the petition of complaint that the report of C.T.Scan of whole abdomen dated 17.11.2012 of Apollo Hospitals, Chennai, report dated 4.12.2012 of Fortis Hospital, Kolkata and ‘Discharge Summary’ UHID 2467449 of Apollo Hospitals, Chennai, indicate the defect in “laparoscopic cholecystectomy” done on 9.8.2012 by OP1-Doctor at OP3-Clinic and resultant medical negligence on behalf of the OPs. In the course of investigation, it was found that there was no stone in gall bladder without any reference to partial cholecystectomy clearly indicates that the whole of the gall bladder was removed. After going through all reports, the Commission asked the hospital and doctors to pay the compensation.
Paying homage to the undying spirit of Stephen Hawking, the genius who recently passed away, The Subrung Theatre Group is staging a show of their play ‘Har Guruvar’, a Hindi play inspired by Mitch Album’s best selling world classic: “Tuesdays with Morrie” on April 20, from 7:30 p.m. onward at Shri Ram Centre, Mandi House.This inspiring play tells the story of a man, ‘Professor Sapre’ who is dying because of Motor Neuron Disease, which, only a few days ago, took the life of Stephen Hawking. But that’s not the only thing they have in common. Like Hawking, Sapre refuses to let impending death bog him down. Also Read – Add new books to your shelfProf Sapre likes Hawking because he lived his life to the fullest in spite of suffering from Motor Neuron Disease. The play was directed by Rajinder Nath, multiple National award winner and a Hindi theatre personality regarded as indispensable for contemporary Indian drama.This popular play has not only received critical praise but was also invited by the National School of Drama to participate in the 8th Theatre Olympics, where the play was performed in front of a full house audience.The cast of the play includes names like Manu Sikander Dhingra, Sanjiv Johri, Mala Kumar, Rekha Malhotra Johri and others.
Kolkata: A day after slamming the Centre for highest unemployment rate in the country in 45 years, West Bengal Chief Minister Mamata Banerjee on Monday urged the youngsters to raise questions on growing joblessness. Banerjee assured support to the youth on the occasion of the International Youth Day. “Today is International #YouthDay. In #Bangla, we celebrate Youth Day on January 12, Swami Vivekananda’s birth anniversary. I appeal to the youth, the students & the new generation: be strong and ask for answers. There is no answer to unemployment problems,” she tweeted. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: Mamata Referring to central government data that put West Bengal at the top of the states with highest GDP growth, Banerjee said unemployment in the state has dipped by 45 per cent under her rule. “Our State #Bangla has brought down unemployment by 45%. The GDP growth of #Bangla is highest in the country. My support is always with the youth, students and the new generation. May you be inspired to reach new heights,” she said. As per the data, West Bengal has registered a GDP growth rate of 12.58 per cent in 2018-19 while unemployment rate was 6.1 percent during the period. Banerjee had written on Facebook on Sunday,”Our achievement is in sharp contrast to the state of deep recession and complete policy paralysis perpetrated by Central Government leading to significant decline of overall growth rate of the country and highest unemployment in 45 years”.