Tunneling Electrons Do Math

first_imgIn brief, here’s how it works: The value of charge reservoir Q is reset to zero before each computation, and electrons tunnel from Q to reservoir Q x D, one at a time, until the value of reservoir Q x D equals that of reservoir Z. The final answer to the problem is the value of reservoir Q; since removing electrons increases the value of the reservoir, this is a positive value. The researchers improved this simple but limited design by transferring electrons in groups using a “building blocks” method, which decreased unwanted delay and could calculate a remainder. In reservoir Q, electrons are grouped in blocks in logarithmic numbers (e.g. in groups of 1, 2, 4, 8, etc.). An electron block estimates if its transfer would cause the value of reservoir Q x D to exceed that of reservoir Z. If so, the electron block is not transferred, and the next smaller electron block evaluates the same condition. For example, for 22 divided by 4, one block of 4 electrons, zero blocks of 2 electrons, and one block of 1 electron are transferred to create a positive charge of 5 in reservoir Q. The remainder is calculated with a subtraction block, which evaluates the difference between the values of reservoirs Z and Q x D (in this case, 22-20=2).The researchers’ third scheme is fine-tuned further, and is based on the computation of periodic symmetric functions (PSF). A PSF block based on an electron trap has a periodic transfer function, of which the period can be dynamically adjusted by using a voltage controlled capacitor. A device called a varactor would be used in place of a capacitor, which is currently still theoretical for the nanoscale. The PSF scheme resulted in the best performance out of the three schemes, with a worst-case delay of 18 ns and a worst-case energy consumption of 2.3 eV. Meenderinck explained that an accurate comparison to CMOS is difficult, but to give an idea of the difference, he looked at a recent publication on CMOS dividers (‘Low Power Self-Timed Radix-2 Division,’ Jae-Hee Won and Kiyoung Choi, ISLPED, 2000). “We calculated a delay of 18 ns and an energy consumption of 3.7e-19 J,” he said. “The scheme of Won and Choi has a delay of 33.8 ns and an energy consumption of 3.4e-9 J. Clearly, the energy consumption is the key benefit of our SET circuit. Considering that power has become one of the main design constraints, SET becomes a serious candidate for the post-CMOS era.”Meenderinck also added that, although the latency of the two circuits does not appear to differ much, that number could change when using alternative equations. “We used the equations of the orthodox theory, which is generally accepted by the research community in the field,” he said. “However, there are some researchers (mainly from the circuit theory area) that disagree with this theory. For example, J. Hoekstra proposed a circuit theory (‘On the impulse circuit model for the single-electron tunnelling junction,’ International Journal of Circuit Theory and Applications, 2004) in which the delay is calculated as the RC product of the circuit. Using this theory, the delay we report would be much smaller—reduced by a factor of 100 or more.”For engineers who use SET to look beyond traditional ways of computation, Meenderinck and Cotofana predict that the technique has the potential to make many such improvements in future computing.Citation: Meenderinck, Cor and Cotofana, Sorin. “Computing Division Using Single-Electron Tunneling Technology.” IEEE Transactions on Nanotechnology, Vol. 6, No. 4, July 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. 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. Researchers develop new way to measure fluid-rock interaction in oil reservoir Using a novel computing paradigm involving counting single electrons, computer engineers have designed nano-sized circuitry that allows tunneling electrons to perform mathematical division calculations. Explore further Citation: Tunneling Electrons Do Math (2007, August 2) retrieved 18 August 2019 from https://phys.org/news/2007-08-tunneling-electrons-math.html While other methods utilizing quantum mechanical behavior have been proposed to increase computing power, these technqiues have yet to take full advantage of quantum mechanical properties on the nanoscale—namely, high speed and low power consumption.Cor Meenderinck, a PhD student in Computer Engineering, and Sorin Cotofana, an Associate Professor in Computer Engineering, from the Delft University of Technology in the Netherlands, have recently published their research on a quantum mechanical behavior called single-electron tunneling (SET) in IEEE Transactions on Nanotechnology. Building on their past SET paradigms that perform addition and multiplication operations, Meenderinck and Cotofana have presented three schemes that use tunneling electrons to quickly divide.Electron tunneling is a phenomenon on the quantum scale that enables single electrons to “jump” across forbidden energy states due to their wave-like properties. A few scientists have recently been experimenting with SET circuits based on tunnel junctions that consist of a thin insulating material layered between conducting material. Although charge transport across an insulator is prohibited in classical mechanics, electrons can tunnel one at a time through an ultrathin insulator in quantum mechanics. Electrons can represent bits, making SET a potential candidate to succeed CMOS technology.“As far as we know, very few people have been designing circuits with SET and we are not aware of any division implementations,” Cotofana told PhysOrg.com. “Thus comparison is limited to CMOS. Our circuits basically compute analog values. However, due to the discreteness of electrons (if the circuit is designed properly, an electron tunnels or not and electrons are localized on either side of the junction) we end up with digitized values; that is, the number of electrons present in a reservoir is the represented value.”Meenderinck’s and Cotofana’s first SET design to perform division was based on a sequential approximation of the quotient. The scheme uses electron counting, with three charge reservoirs that store electrons for the dividend Z, quotient Q, and product of Q and the divisor D (Q x D). last_img read more

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RCAs Airenergy charger converts WiFi energy to electricity

first_img Citation: RCA’s Airenergy charger converts WiFi energy to electricity (2010, January 13) retrieved 18 August 2019 from https://phys.org/news/2010-01-rca-airenergy-charger-wifi-energy.html Harvesting electricity from signals in the air is not new, as anyone who ever built a crystal radio running only on the radio signals it received can testify, but until now no device has been able to harvest enough electricity to make it of practical use. In most modern cities WiFi signal hotspots abound, which might make the Airenergy device a viable option, although in rural areas WiFi sources are less widespread.A USB charger costing around $40, and about the size of a phone, is expected to be released later this year, with a WiFi-harvesting battery around the same size and price as an OEM battery available shortly after. (PhysOrg.com) — Airenergy is a gadget that can harvest free electricity from WiFi signals such as those from a wireless Internet connection, apparently with enough efficiency to make it practical for recharging devices such as mobile phones. 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 furthercenter_img Analyst cool on Chicago citywide WiFi plan At the Consumer Electronics Show (CES) in Las Vegas this week a RCA spokesman said they had been able to charge a BlackBerry from 30% charge to fully charged in around 90 minutes using only ambient WiFi signals as the power source, although it was unclear on whether the Airenergy battery was recharged in that time. The Airenergy recharging time depends on the proximity to the WiFi signal and the number of WiFi sources in the vicinity.The RCA Airenergy unit converts the WiFi antenna signal to DC power to recharge its own internal lithium battery, so it automatically recharges itself whenever the device is anywhere near a WiFi hotspot. If you have a wireless network at home the Airenergy would recharge overnight virtually anywhere in your home. When you need to recharge your phone or other device you plug the Airenergy battery into the phone via USB to transfer the charge. © 2010 PhysOrg.comlast_img read more

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Flocking robots take to the sky w video

first_img Researchers Sabine Hauert, Sebverin Leven and Dario Floreano have discovered a way to make small, fixed wing robots take to the sky and fly together without crashing and migrate. In order to accomplish this, the researchers needed to make the robots move at the same speed and direction, avoid collision and stay in close proximity. They will be presenting their work this week in San Francisco at the International Conference on Intelligent Robots and Systems. (PhysOrg.com) — The next time you look up in the sky and think you are seeing a flock of geese flying south for the winter, take a closer look. If you are in Lake Geneva, Switzerland, these flocks may actually be robots from the Laboratory of Intelligence Systems. More information: lis.epfl.ch/smavs In order to accomplish this, the researchers used a three-dimensional algorithm developed by Craig Reynolds in 1986 where the individual robots responds to its close neighbor but does not consider the actions of the group as a whole.The robots were created by the robotics company senseFly and communicate with each other using a Wi-Fi dongle that is connected to an on-board Linux computer. They began with simple testing and have reached a total of 10 flocking birds at one time but simulations show they could use up to 100 flocking robots.In addition to programming the robots to fly at the same speed, stay close and not collide, the researchers also added something else. They added the ability to migrate. This allows the researchers to set a pre-programmed destination for the swarm to travel to. The intended use for these flocking robots is to image and map the ground as well as the potential to be used for search and surveillance missions. Kilobots bring us one step closer to a robot swarm 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: Flocking robots take to the sky (w/ video) (2011, September 27) retrieved 18 August 2019 from https://phys.org/news/2011-09-flocking-robots-sky-video.html © 2011 PhysOrg.com Explore furtherlast_img read more

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High school student develops supercapacitor wins Young Scientist Award

first_img Explore further (Phys.org) —Saratoga California high school student Eesha Khare is a co-winner of this year’s Young Scientist Award sponsored by Intel. She won the award for her battery-sized supercapacitor design which allows for recharging in just a few seconds. The award was part of Intel’s International Science and Engineering Fair. Top winner Ionut Budisteanu, 19, of Romania (center) with second-place winners Eesha Khare, 18, of Saratoga, Calif. (left) and Henry Lin, 17, of Shreveport, La. celebrate their awards at the Intel International Science and Engineering Fair, the world’s largest high school science research competition. More than 1,600 high schoolers from 70 countries, regions and territories competed for more than $4 million in awards this week. Engineers craft new material for high-performing ‘supercapacitors’ More information: www.intel.com/content/www/us/e … ng-fair/winners.html Citation: High school student develops supercapacitor, wins Young Scientist Award (2013, May 20) retrieved 18 August 2019 from https://phys.org/news/2013-05-high-school-student-supercapacitor-young.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. Khare’s supercapacitor is meant to serve as a replacement for a small battery, specifically those used in cell phones. She says the inspiration for her design came out of frustration from constantly finding her cell phone battery dead. The supercapacitor she developed is small enough to fit inside a standard cell phone battery housing, and can be fully charged in just 20 to 30 seconds. As if that weren’t enough, it also has a much longer useful life offering 10,000 charge/recharge cycles instead of the 1,000 available now for batteries. The supercapacitor is based on nanochemistry, which Khare told the crowd during her acceptance speech is her main area of scientific interest.As cell phones have grown smarter and more powerful, concern has grown over the ability of battery development to keep up. Khare’s supercapacitor suggests that perhaps there is a better way. Capacitors are devices used to store an electronic charge—though typically little more than conductors separated by an insulator, they are an essential component of most electronic devices. They help regulate the flow of electricity. They can also be used as a battery, however, as Khare’s device demonstrates. Thus far, hers is only capable of powering an LED, but that is likely to change with advances in nano-technology.The award comes with a $50,000 cash prize, which Khare will likely use for college; although, this prize might also help her win a scholarship. She plans to continue her research on the supercapacitor with the ultimate goal of replacing her cell phone battery. She noted that such a supercapacitor would also be useful for powering a wide variety of other devices, adding that it’s also flexible. It could be used to power devices embedded in clothes, she suggested, or as part of roll-top electronic devices. © 2013 Phys.orglast_img read more

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Physicists propose a second level of quantization for quantum Shannon theory

first_img For identical quantum channels, order matters In the past two decades, physicists have been developing a quantum version of information theory in which the internal state of each information carrier has quantum properties, such as superposition—the ability to occupy two or more classical states at once. But the transmission lines are generally still assumed to be classical, so that the path taken by messages in space is always well-defined.Now in a new paper, physicists Giulio Chiribella and Hlér Kristjánsson at the University of Oxford and the University of Hong Kong have proposed a second level of quantization, in which both the information carriers and the channels can be in quantum superposition. In this new paradigm of communication, the information carriers can travel through multiple channels simultaneously. “This work provides the foundation for a new theory of communication where the propagation of information in space and time is treated quantum mechanically,” Chiribella told Phys.org. “It opens up new avenues for quantum communication networks and for a future quantum internet, where data could be sent from a sender to a receiver through multiple quantum servers. Exploiting the interference of different communication paths, it will be possible to communicate more efficiently and more securely. At the fundamental level, the transmission of messages along multiple trajectories could give rise to fundamental tests of the quantum nature of spacetime.”This channel superposition phenomenon can be observed in the famous double-slit experiment, in which a single photon seems to pass through two slits at once. Even though just a single photon is used, the photon creates an interference pattern on the detector. The best explanation for the interference pattern is that the photon interfered with itself, like a wave, after simultaneously traveling through both slits along two different paths. Journal information: Proceedings of the Royal Society A Information theory, which was developed by Claude Shannon starting in the late 1940s, deals with questions such as how quickly information can be sent over a noisy communications channel. Both the information carriers (e.g., photons) and the channel (e.g., optical fiber cable) are assumed to be classical systems, with well-defined, perfectly distinguishable states. When an information carrier is allowed to travel through two communications channels simultaneously, it can offer advantages such as reduced noise (due to the interference of noise on different paths) and a higher channel capacity. These advantages have been demonstrated in recent experiments with photons. In the new paper, the physicists had to confront some of the challenges involved in incorporating the superposition of channels into a quantum theory of information. One of the challenges is to describe the superposition of channels in a compositional way, so that the behavior of a channel can be predicted when it is used in combination with other channels. A second challenge is that the superposition of internal states of the information carriers must be clearly separated from the superposition of paths. Otherwise, the path itself becomes part of the message, and the system can be described using the conventional quantum framework. By addressing these challenges, the physicists formulated a quantum communications model that can be used to compute the amount of information that can be reliably transmitted when using a given number of channels in a quantum superposition. Counterintuitively, the physicists showed that, for certain types of noise, the superposition of channels, along with the ability to switch a channel with itself, could be used to completely remove all noise. This opens up the possibility of obtaining perfect quantum communication in a noisy channel.”Our work defined a communication model and provided a few proof-of-principle examples,” Chiribella said. “However, this has only scratched the surface of what can be accomplished with the superposition of quantum communication channels. We are now exploring the power of correlations among them. If two trajectories visit the same region, the process experienced by the information carrier in the first trajectory can be correlated with the process experienced in the second trajectory. By taking advantage of these correlations in a clever way, it is possible to enhance the communication performance beyond what can be done with the superposition of independent channels. Getting ahold of these correlations will give us new insights into the peculiar ways in which quantum information propagates in space and time.” Explore further More information: Giulio Chiribella and Hlér Kristjánsson. “Quantum Shannon theory with superpositions of trajectories.” Proceedings of the Royal Society A. DOI: 10.1098/rspa.2018.0903 Citation: Physicists propose a second level of quantization for quantum Shannon theory (2019, May 22) retrieved 18 August 2019 from https://phys.org/news/2019-05-physicists-quantization-quantum-shannon-theory.html © 2019 Science X Network The superposition of N channels allows information carriers to travel through multiple channels simultaneously. Credit: Chiribella and Kristjánsson. ©2019 The Royal Society 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. 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Mamata lashes out at Centre for trying to curb freedom of Press

first_imgKolkata: Criticising the Centre’s step to “curb freedom of Press” in the name of controlling fake news as a “draconian move”, Chief Minister Mamata Banerjee has demanded immediate withdrawal of the circular of suspending or cancelling accreditation of journalists.Banerjee tweeted: “The PIB circular on #FakeNews control is a brazen attempt to curb Press freedom, a sure sign that the Govt has lost its way. We demand the immediate withdrawal of such a draconian move.” Also Read – Heavy rain hits traffic, flightsIn the tweet, she also took a dig at BJP, without taking its name, in connection with the circulation of fake news: “And what about #FakeNews spread by a political party on a regular basis?”It may be recalled that the Chief Minister was the first to raise her voice against circulation of fake news, mainly through social media, to purposely create trouble. She had repeatedly urged people to ignore such news and also directed the police to maintain a vigil so that such news doesn’t get circulated.It may be mentioned that when allegations of attempting to curb freedom of journalists rose against the Centre, the Mamata Banerjee government has issued a notification to give pension to journalists above 60 years as a “respect and responsibility of the state on democracy”.The Centre was forced to withdraw the move in the wake of severe criticism.last_img read more

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Son asked Will Smith to hit gym before Focus

first_imgActor Will Smith says his 16-year-old son Jaden urged him to go to the gym before starring alongside Margot Robbie in the film Focus. Jaden urged his 46-year-old father to tone-up after he was cast alongside the 24-year-old Australian beauty in the romantic comedy-drama, in which he plays a veteran con artist who takes Robbie’s on-screen character Jess under his wing, reports femalefirst.co.uk. Speaking on the British TV show Good Morning Britain, Smith said: “When Margot got hired for the film, Jaden said: ‘Get in the gym – do not embarrass me.’last_img

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Passenger arrested at Kolkata airport for carrying psychotropic substance

first_imgKolkata: A passenger, resident of Uttar Panchpota, North XXIV Parganas, travelling to Doha by Qatar flight no. QR- 541 was arrested on Tuesday at Netaji Subhas Chandra Bose International Airport in Kolkata, for carrying 1865 tablets of amphetamine. Amphetamine is a psychotropic substance under NDPS (Narcotic Drugs and Psychotropic Substances) Act, 1985. A customs office press release read, 1865 pieces of amphetamine, weighing 200 grams, were seized under Section 43 of NDPS Act, 1985. The passenger was arrested under the provision of the act ibid. Further investigation is in progress.last_img

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E Railway pitches for womens security hygiene

first_imgThe Eastern Railway has stepped up efforts to improve the quality of services, including catering and security, provided to the passengers in the trains and railway stations. Women’s security is on the top agenda of the Eastern Railway with lady constables being provided in trains, officials said on Monday. Under Swachh Bharat Mission special drives across railway premises are also being conducted. Also Read – Need to understand why law graduate’s natural choice is not legal profession: CJI”Ladies Special Trains (EMU) are escorted. Late night EMUs and early morning EMUs are also escorted, including by lady constables. Extra vigil is kept by escort parties over ladies compartments of mail, express and passenger trains,” an official said, explaining about the steps taken by the Eastern Railway for women’s security.  The Eastern Railway has also conducted drive against males travelling in ladies compartments and 16, 310 persons were apprehended. Also Read – Health remains key challenge in India’s development: KovindIn a bid to improve the quality of food, regular inspections and week long drives are undertaken by officials, and all the officers travelling on duty have been instructed to inspect pantry car and food quality. “We undertake intensive cleaning of pantry cars and officials undertake random inspection of pantry cars and on-board catering services. Drastic action is taken for any lapse,” an official said, explaining about the steps taken to improve the quality of services.  Talking about the future plans to improve catering services, he said that sites for base kitchen at Howrah, Sealdah and Asansol have been selected.Besides trains, special effort are being taken to clean the railway stations also.  “Mechanized cleaning has been introduced in all A1, AII and most B&C category stations. Rag picking contracts, garbage removal contracts at all A1, A, B,C &D category stations have recently started,” an official said. The workshops of the Railways like Kanchrapara, Liluah, Jamalpur have also performed well and given good outputs as per expectations.last_img read more

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Showcasing Bengals culture and heritage

first_imgLeather bags and boxes from Shantiniketan, straw mats from Midnapore, contemporary colourful terracotta jewellery from Kolkata besides Patachitra on T-shirts and sarees, intricate katha stitches on crepe are among the range of products.The fourth edition of the Bengal Pre-Puja Exposition organised by Office of the Resident Commissioner, West Bengal government began from September 16 is scheduled to continue till September 30. “I have won national award for making this particular mat which is light and is completely foldable. It costs Rs 25,000 and I have bought it for the exhibit here. There are other pieces here also and its price depends on the finesse of the product,” says Tapas Jana, an expert in making mats who hails from Paschim Midnapore. Also Read – ‘Playing Jojo was emotionally exhausting’Jana’s mats are contemporary and stylish with a wide range of colours. They come in various sizes and quality and can be used as carpets too. The famous patachitra from Bengal is being implemented in unique styles on T-shirts, sarees, Duppattas and half shirts.Known for their colour themes and designs, Rahim Chitrakar family is quite popular in their village for this variation of the rural artform. “The art of Patachitra has been in my family from generations. Along with my wife I decided to divulge into implementing this style on apparels. We wanted to carry on the legacy but not on paper as a painting. Our starting price for a T-shirt is Rs 300 and for a saree it is around Rs 5000,” Chitrakar said. Also Read – Leslie doing new comedy special with NetflixSold out on day one of the exhibition itself, Noorjahan Begum another national award winning craftswoman from Bengal’s Burdwan district is awed by demand by customers for her latest creation-Kantha Stitch on crepe sarees.“I have brought something new to the exhibition this time. Crepe sarees with Kantha stitch designs on them. It takes time to do these pieces as we cannot even use a frame to steady the design and have to do the stitch completely with a free hand,” Begum said.  Enjoying a scrumptious Bengali meal at the Bijoli grill outlet at Dilli Haat, visitors also have the option of buying contemporary colourful terracotta ornaments to Shantiniketan leather bags.Shantiniketan leather bags have always been a style statement for both the young and the old. This time around these bags are designed along with colourful zari cloth as well as Kantha Stitch which gives it a chic and exclusive look.“I am saving the Kantha stitch purse and bags for upcoming trade fair. For this exhibition I have got my zari collection. Barring the bags I have other products like leather containers, piggy banks etc,” Debabrati Halder said.last_img read more

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