Computer Memory Takes a Spin
Physicists Read Data after Storing It in Atomic Nuclei 112 Seconds
Dec. 16, 2010 — University of Utah physicists stored information for 112 seconds in what may become the world’s tiniest computer memory: magnetic “spins” in the centers or nuclei of atoms. Then the physicists retrieved and read the data electronically – a big step toward using the new kind of memory for both faster conventional and superfast “quantum” computers.
“The length of spin memory we observed is more than adequate to create memories for computers,” says Christoph Boehme (pronounced Boo-meh), an associate professor of physics and senior author of the new study, published Friday, Dec. 17 in the journal Science. “It’s a completely new way of storing and reading information.”
However, some big technical hurdles remain: the nuclear spin storage-and-read-out apparatus works only at 3.2 degrees Kelvin, or slightly above absolute zero – the temperature at which atoms almost freeze to a standstill, and only can jiggle a little bit. And the apparatus must be surrounded by powerful magnetic fields roughly 200,000 times stronger than Earth’s.
“Yes, you could immediately build a memory chip this way, but do you want a computer that has to be operated at 454 degrees below zero Fahrenheit and in a big national magnetic laboratory environment?” Boehme says. “First we want to learn how to do it at higher temperatures, which are more practical for a device, and without these strong magnetic fields to align the spins.”
As for obtaining an electrical readout of data held within atomic nuclei, “nobody has done this before,” he adds.
Two years ago, another group of scientists reported storing so-called quantum data for two seconds within atomic nuclei, but they did not read it electronically, as Boehme and colleagues did in the new study, which used classical data (0 or 1) rather than quantum data (0 and 1 simultaneously). The technique was developed in a 2006 study by Boehme, who showed it was feasible to read data stored in the net magnetic spin of 10,000 electrons in phosphorus atoms embedded in a silicon semiconductor.
The new study puts together nuclear storage of data with an electrical readout of that data, and “that’s what’s new,” Boehme says.
The study was led by Boehme and first author Dane McCamey, a former research assistant professor of physics at the University of Utah and still an adjunct assistant professor. His main affiliation now is with the University of Sydney. Other co-authors were Hans van Tol of the National High Magnetic Field Laboratory in Tallahassee, Fla., and Gavin Morley of University College London.
The study was funded by the National High Magnetic Field Laboratory, the National Science Foundation, the Australian Research Council, Britain’s Engineering and Physical Sciences Research Council and the Royal Commission for the Exhibition of 1851, a British funding agency led by Prince Philip.
Of Electronic and Spintronic Memories
Modern computers are electronic, meaning that information is processed and stored by flowing electricity in the form of electrons, which are negatively charged subatomic particles that orbit the nucleus of each atom. Transistors in computers are electrical switches that store data as “bits” in which “off” (no electrical charge) and “on” (charge is present) represent one bit of information: either 0 or 1.
Quantum computers – a yet-unrealized goal – would run on the odd principles of quantum mechanics, in which the smallest particles of light and matter can be in different places at the same time. In a quantum computer, one quantum bit or “qubit” could be both 0 and 1 at the same time. That means quantum computers theoretically could be billions of times faster than conventional computers.
McCamey says a memory made of silicon “doped” with phosphorus atoms could be used in both conventional electronic computers and in quantum computers in which data is stored not by “on” or “off” electrical charges, but by “up” or “down” magnetic spins in the nuclei of phosphorus atoms.
Externally applied electric fields would be used to read and process the data stored as “spins” – just what McCamey, Boehme and colleagues did in their latest study. By demonstrating an ability to read data stored in nuclear spins, the physicists took a key step in linking spin to conventional electronics – a field called spintronics.
Spin is an unfamiliar concept to comprehend. A simplified way to describe spin is to imagine that each particle – like an electron or proton in an atom – contains a tiny bar magnet, like a compass needle, that points either up or down to represent the particle’s spin. Down and up can represent 0 and 1 in a spin-based quantum computer.
Boehme says the spins of atoms’ nuclei are better for storing information than the spin of electrons. That’s because electron spin orientations have short lifetimes because spins are easily changed by nearby electrons and the temperature within atoms.
In contrast, “the nucleus sits in the middle of an atom and its spin isn’t messed with by what’s going on in the clouds of electrons around the nucleus,” McCamey says. “Nuclei experience nearly perfect solitude. That’s why nuclei are a good place to store information magnetically. Nuclear spins where we store information have extremely long storage times before the information decays.”
The average 112 second storage time in the new study may not seem long, but Boehme says the dynamic random access memory (DRAM) in a modern PC or laptop stores information for just milliseconds (thousandths of a second). The information must be repeatedly refreshed, which is how computer memory is maintained,” he adds.
How to Store and Then Read Data in the Spins of Atomic Nuclei
For the experiments, McCamey, Boehme and colleagues used a thin, phosphorus-doped silicon wafer measuring 1 millimeter square, and placed electrical contacts on it. The device was inside a supercold container, and surrounded by intense magnetic fields. Wires connected the device to a current source and an oscilloscope to record data.
The physicists used powerful magnetic fields of 8.59 Tesla to align the spins of phosphorus electrons. That’s 200,000 times stronger than Earth’s magnetic field.
Then, pulses of near-terahertz electromagnetic waves were used to “write” up or down spins onto electrons orbiting phosphorus atoms. Next, FM-range radio waves were used to take the spin data stored in the electrons and write it onto the phosphorus nuclei.
Later, other pulses of near-terahertz waves were used to transfer the nuclear spin information back into the orbiting electrons, and trigger the readout process. The readout is produced because the electrons’ spins are converted into variations in electrical current.
“We read the spin of the nuclei in the reverse of the way we write information,” Boehme says. “We have a mechanism that turns electron spin into a current.”
Summarizing the process, Boehme says, “We basically wrote 1 in atoms’ nuclei. We have shown we can write and read [spin data in nuclei],” and shown that the information can be repeatedly read from the nuclei for an average of 112 seconds before all the phosphorus nuclei lose their spin information. In a much shorter time, the physicists read and reread the same nuclear spin data 2,000 times, showing the act of reading the spin data doesn’t destroy it, making the memory reliable, Boehme says.
Reading out the data stored as spin involved reading the collective spins of a large number of nuclei and electrons, Boehme says. That will work for classical computers, but not for quantum computers, for which readouts must be able to discern the spins of single nuclei, he adds. Boehme hopes that can be achieved within a few years.
Reference Link
http://www.unews.utah.edu/p/?r=120610-2
Courtesy
The University of Utah
Social media for social change: Stanford professor uses Facebook, Twitter and personal stories to promote bone marrow donations
Samir Pendse’s cousin, Sonali Patwardhan, left, and aunt, Amrita Lokre, register Vaibhav Lole at a bone marrow donor drive held recently at a Hindu temple in Fremont. Lole was one of 62 people who became potential donors at the event to help Pendse, who has leukemia. (Photo by Adam Gorlick)
Using online social networks to register more Indians as bone marrow donors has become both a Good Samaritan cause for Jennifer Aaker and part of her curriculum. She’s spearheading a campaign relying on social media to get 100,000 more people signed up with the national bone marrow donor registry. And she’s working with students from Stanford’s Haas Center for Public Service to help them organize around a specific cause that has deep meaning to them.
Samir Pendse was diagnosed with leukemia in 2003.
BY ADAM GORLICK
One email is all it took for Chaitali Nadig to try saving a life.
The message advertised an upcoming bone marrow drive to benefit Samir Pendse, an 18-year-old battling relapsed leukemia. A marrow transplant is one of his best hopes for a cure.
“Due to the stage of his disease, he has a very short time window,” the email stressed. “Hence the need is URGENT.”
The email – sent by the Fremont Hindu Temple to its members – included a picture of Samir. He’s smiling.
“I had to come here today,” Nadig said outside the temple this past Sunday. She had just rubbed a few cotton swabs along the inside of her check to produce a DNA sample that will show whether she’s a potential bone marrow donor for Samir or someone else needing a transplant.
“Looking at this kid’s face in the email and seeing how brave he is made me want to do something,” she said. “And doing this cheek swab has almost no effect on my life, but it could save someone else’s.”
Marrow matches are almost always made among people of the same ethnic origin. And with only about 140,000 South Asians in the national bone marrow donor registry, Samir – who was born in Fremont a decade after his parents moved to California from India – learned quickly that a match would be hard to find.
Sunday’s drive drew 62 people affiliated with the temple. Hardly any of them knew Samir or his relatives. But many said they read the same email that Nadig received or saw a related Facebook site maintained by Samir’s family. And that was enough of a nudge to get them to show up.
Professor Jennifer Aaker is spearheading One Hundred Thousand Cheeks, a campaign relying on social media to get 100,000 more people signed up for the national bone marrow donor registry.
“When you learn about something from your friends or people you trust through email or Facebook, it’s much more persuasive than a message coming from a corporation or someone you don’t know,” said Jennifer Aaker, a marketing professor at Stanford’s Graduate School of Business who is helping attract attention to Samir’s search for a donor.
“When a request comes from an area of deep personal meaning by someone you trust, you are more likely to take action,” she said.
Social media for social change
The idea that online social media can inspire people to take small, individual steps that snowball into significant social change is at the heart of Aaker’s work at Stanford.
And using those tools to register more Indians as marrow donors has become both a Good Samaritan cause for Aaker and part of her curriculum. She’s spearheading One Hundred Thousand Cheeks, a campaign relying on social media to get 100,000 more people signed up with the national bone marrow donor registry through cheek swab drives like the one held at the Fremont temple.
Aaker is working with students from Stanford’s Haas Center for Public Service to help them organize around a specific cause that has deep meaning to them – and in the process tell the story of people like Samir and Sanjana Sahni, a mother of twins living in Sunnyvale, Calif., who needs a marrow transplant to combat her multiple myeloma.
“Our hope is to harness research on social persuasion, happiness and emotional contagion to create infectious action,” Aaker said.
She was recently in India – where she’s pushing for the creation of a country-wide bone marrow registry – to give several presentations about her work with online social networking. She coupled those talks with three marrow registration drives that helped enlist more than 300 potential donors. Aaker holds similar events at Stanford and Bay Area companies.
“I used to think social networking was a waste of time,” Aaker said. “I thought the more time you spend on Facebook and Twitter, the more narcissistic and self-involved you become. But it became clear that social media can be used to amplify altruism and create social good in the world.”
Chaitali Nadig registers as a potential bone marrow donor by swabbing her cheek to produce a DNA sample at the Fremont event.
Lessons from a student
That realization came a few years ago after Robert Chatwani, one of Aaker’s students at the time, told her about Sameer Bhatia. Bhatia, a friend of Chatwani’s who received his bachelor’s degree from Stanford in 1997, was diagnosed with leukemia in 2007.
Facing a 1-in-20,000 chance of finding a donor to match his Indian DNA, Bhatia and his friends devised a strategy using emails, Facebook and YouTube to spread the word urging South Asians to register as marrow donors. Their online campaign became viral. Within 11 weeks, they managed to log 24,611 South Asians in the national bone marrow registry.
Bhatia found his match and received a marrow transplant. Although he died a few months later, his story inspired Aaker to teach a class on how to harness social technology to create social good. Her teaching and research blossomed into The Dragonfly Effect, a recently published book that highlights Bhatia’s story and other cases where social media were used to focus attention on a cause and rally large numbers of people to take action.
And her work has attracted those who are in most need of her help.
Close calls and another hope
Samir Pendse’s parents contacted Aaker and plugged into her social network in November, shortly after doctors told them the 18-year-old’s leukemia had returned.
Samir was first diagnosed in 2003, a shock followed by three years of chemotherapy treatments that often kept him out of school and off the playground.
“It was a very hard treatment,” said his aunt Amrita Lokre. “And it made it even harder to see all of his friends outside playing and doing everything he wanted to do but couldn’t.”
The chemo battered his cancer into remission. And in the summer of 2007, Samir and his family celebrated with a trip to visit relatives in India.
But good health didn’t last very long. Shortly after returning home, the leukemia – and the treatments – were part of his life once again. But his family also learned that a bone marrow transplant offered hope for a cure, and they started organizing marrow drives throughout the Bay Area.
They advertised the events among the local Indian community using email and talking to as many people as they could.
“It was an uphill battle,” said Samir’s cousin Chetan Patwardhan.
He figures the family’s efforts paid off by getting about 2,000 people signed into the bone marrow registry. And early on, a match for Samir was found. But the potential donor backed out.
“There’s a misunderstanding of what it takes to donate marrow,” Lokre said. “People think it will hurt or maybe make them sick. But that isn’t true, and they just don’t realize that.” During the procedure, marrow is drawn from the pelvic bones with a needle and syringe. Most donors are released from the hospital hours later.
By early 2010, Samir’s leukemia went into remission once again.
Now the cancer is back. And this time, chemotherapy won’t work. Samir is scheduled to receive a cord blood transplant – a promising alternative to a marrow transplant – just before the new year.
Once again, he came close to having a marrow transplant. A potential donor who registered during one of the drives Aaker helped organize in Mumbai was an almost perfect match for Samir. But timing and logistics scuttled that chance.
Still, the hope was found – half a world away, but within reach in a growing network of people realizing their small steps could create a big change in someone’s life.
Reference Link
http://news.stanford.edu/news/2010/december/aaker-marrow-registry-121610.html
Courtesy
Stanford University
UMass Amherst Scientist Helps Design System Using RFID Devices to Guide Blind Visitors inside Unfamiliar Buildings
AMHERST, Mass. –
An electronic system developed by Aura Ganz, professor of electrical and computer engineering at the University of Massachusetts Amherst, allows visually impaired people to safely navigate unfamiliar buildings using a three-ounce electronic device and a Bluetooth headphone.
The system, called PERCEPT, uses Radio Frequency Identification (RFID) tags placed throughout a building as audio landmarks. When a visually impaired person tunes into these electronic signposts with an RFID reading device, the system provides verbal instructions through the headphones. Ganz heads a research team working on the project through a three-year, $380,000 grant from the National Institutes of Health/National Eye Institute.
Unfamiliar buildings pose a huge challenge for blind and visually-impaired people. Current training programs to help them, including at UMass Amherst, require memorizing a large amount of information for many buildings each semester, and this can lead to confusing and frustrating situations.
Ganz is trying to deal directly with the problems associated with vision impaired people and their ability to get around. She has a pilot project in the works. “We do have a basic prototype of the PERCEPT system already built,” Ganz says. “It will be installed by June of 2011 in the Knowles Engineering Building on the UMass campus, where human testing will begin this summer.”
At any entrance of Knowles, the visually impaired person will be able to get directions to every room in the building at a kiosk where the PERCEPT system will orient them with audio instructions. The kiosk has an outline of the building layout represented using raised and Braille alphabet. Using the kiosk, you enter a desired floor, room number or another destination, such as a restroom or elevator, to get simple directions spoken into the headset. As the user follows those directions, the hand-held PERCEPT device can scan the RFID tags that serve as signposts along the way, and further directions are relayed to the headset.
The project has been conducted with suggestions from Carole Wilson, the certified orientation and mobility specialist from the Massachusetts Commission for the Blind, located in Springfield. She is also helping Ganz by recruiting 20 visually impaired subjects from around western Massachusetts to test the PERCEPT system in the Knowles building. These are people unfamiliar with the UMass Amherst campus.
It’s important that the test subjects have no prior knowledge of the building layout, Ganz says. “This system was created to be deployed in any building, and it’s geared toward visually impaired visitors who have never been there before. PERCEPT should work for visually impaired people entering any building for the first time. Our goal is to produce this technology for public buildings everywhere.”
Other members of the PERCEPT research team are Russ Tessier, professor of electrical and computer engineering, who is developing the miniaturized hardware for the RFID reading device, and Elaine Puleo, research associate professor from the School of Public Health and Health Sciences, who is working on the experimental design.
Reference Link
http://www.umass.edu/newsoffice/newsreleases/articles/117625.php
Courtesy
University of Massachusetts Amherst
Google's 'fossil record' digitises 5 million books
For the first time, humanities scholars can crunch numbers with the best of their natural-science colleagues, thanks to Google’s “fossil record” of 5 million books, spanning 500 years.
Already, researchers have traced the accelerating evolution of the English language, mapped the rise and fall of various people, and uncovered patterns of censorship and suppression in Soviet Russia, modern China, and 1950s America – and that’s only a beginning.
“This dataset is going to underwrite a field which is far, far more interesting than anything we could talk about in a single paper,” says Erez Lieberman Aiden, an applied mathematician and bioengineer at Harvard University who led the research along with Jean-Baptiste Michel, also of Harvard.
Until now, scholars in the humanities have tended to read a relatively small number of texts in detail, just hundreds or thousands at the most. This let them form a subjective picture that does not lend itself to statistical analysis. However, in recent years Google has set out to create digitised versions of the full text of millions of books.
From the more than 15 million books digitised to date, Aiden, Michel and colleagues from Google and Harvard selected the 5.2 million with the most reliable data – a total of more than 500 billion words. If written as a single line of text, this would stretch to the moon and back 10 times. Then the researchers counted up the number of times each word appeared in the dataset during each year from 1800 to 2000.
Lexical dark matter
This let them follow changes in word use over this period, as the total number of English words in use rose from 544,000 in 1900 to more than 1 million in 2000, with the vast majority of that increase coming after 1950. (About 52 per cent of those million words do not appear in standard dictionaries, forming what the researchers call “lexical dark matter”.)
Similarly, they tracked the mention of people’s names, a crude measure of fame, and found that people today become famous earlier in life than they used to –an average age of 29 in the mid-20th century, down from 43 in the early 19th century. However, fame today is more fleeting, they found.
The data also show clear evidence of censorship, as certain taboo names disappear from use in certain countries: “Tiananmen Square” in China after 1989, for example. Likewise, “Leon Trotsky” declined sharply in use in Russian books around 1940, and the names of blacklisted Hollywood actors got fewer mentions during anti-communist hysteria in the US.
Quantitative analyses of this sort represent an important new tool for humanities scholars, says Brett Bobley, director of the Office of Digital Humanities at the US government’s National Endowment for Humanities in Washington, DC. “There’s a lot of potential there,” he says. “We’re at a real tipping point.”
Reference Link
http://www.newscientist.com/article/dn19877-googles-fossil-record-digitises-5-million-books.html
Courtesy
Reed Business Information Ltd.
Graduate Students Create Recyclable Laptop
A new laptop designed by students may not self-destruct in 30 seconds, but it can be disassembled in about that amount of time, which makes it easier to safely dispose of when it’s time to throw it out.
A group of seven graduate students, from Stanford University and Finland’s Aalto University, created a prototype of a recyclable laptop as a project for a corporate-sponsored mechanical-engineering class.
The invention, called the Bloom laptop, is made mostly of materials that can be recycled alongside ordinary household items, like metal, plastic, and glass. Materials like LCD screens and circuit boards, which need to be sent to specialized recycling facilities, can be easily separated in a few steps.
“I think where the group really nailed it on the head is where they tried to understand how to modify consumer behavior in a way that would promote green thinking,” said John Feland, who leads the Stanford class involved in the project. “If the design of the computer involves the consumer in the process of changing the environment, it becomes easier for people to do the right thing.”
The group was one of 10 teams in the Stanford engineering design class that received a challenge from a corporate sponsor, Autodesk. The company wanted a completely recyclable consumer-electronics product. However, the choice of the product was completely up to the students.
Aaron Engel-Hall, a Stanford mechanical-engineering graduate student and one of the group members, said making that decision took nearly nine months for the group. Through testing, the group discovered that it took them an average of 45 minutes and 120 steps to dismantle an ordinary laptop.
The students were also intrigued by the relatively short life of a laptop, averaging around two years, since that short life span increased the pace that waste entered the environment. These discoveries, Mr. Engel-Hall said, inspired the group to focus their attention on simplifying the laptop deconstruction process by designing pieces that could slide or snap apart, resulting in an end-product that Mr. Feland calls “where origami meets electronic engineering.”
In addition to encouraging recycling of old laptops, Mr. Feland said the Bloom design could also be both a more economical and greener laptop in other ways. The design makes it easier for consumers to replace the parts themselves, rather than scrap it if something goes wrong, he said.
Mr. Feland acknowledged that there are some minor technical hurdles in the design that need to be overcome before it can be produced for a wider market—such as the prototype’s size and weight.
The design has yet to be embraced by any laptop manufacturers, but all of the ideas are openly available through Autodesk’s Web site. Mr. Feland said corporate-sponsored classes have been a part of Stanford for 45 years, because they allow students to work on solutions for real problems companies are facing with the opportunity to experiment and fail—a luxury he said the real world doesn’t provide.
Reference Link
http://chronicle.com/blogs/wiredcampus/graduate-students-create-recyclable-laptop/28434
Courtesy
The Chronicle of Higher Education
Taiwan disease simulation system publicly unveiled
TAIPEI, Taiwan — Taiwan has become the third country in the world to publicly unveil a disease simulation system capable of predicting the spread of influenza, Academia Sinica said in a statement.
Wang said the new system adapted a revised computing algorithm to an updated database containing population and transportation data and public health statistics provided by Taiwan’s Centers for Disease Control (CDC), enabling it to run 1,000 times faster than other simulators in existence and generate more precise results.
The system has a wide range of applications because it can simulate the outcomes of different quarantine policies, the specialist added.
Though the system was only publicly unveiled this month, it had been researched since 2007 and was tested during the outbreak of swine flu (influenza A H1N1) in Taiwan late last year.
CDC deputy director-general Lin Ting said the simulator concluded that with appropriate airport inspection and quarantine measures, the peak date of infection could be postponed by 22 days, a result that served as an important reference to the Department of Health (DOH) in developing disease control and intervention policies at that time.
Reference Link
http://www.chinapost.com.tw/taiwan/national/national-news/2010/11/22/280888/Taiwan-disease.htm
Courtesy
The China Post
UC Breakthrough May Lead to Disposable e-Readers
Photos By: Dottie Stover; ACS Cover Illustration by Angela Klocke
A breakthrough in a University of Cincinnati engineering lab that could clear the way for a low-cost, even disposable, e-reader is gaining considerable attention.
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| Andrew Steckl is an Ohio Eminent Scholar at UC’s College of Engineering and Applied Science. His latest research involves advances in display technology that achieves electrowetting on paper as opposed to glass. |
Electrical Engineering Professor Andrew Steckl’s research into an affordable, yet high-performance, paper-based display technology is being featured this week as the November cover story of ACS Applied Materials and Interfaces, one of the scientific journals for the American Chemical Society, the world’s largest scientific society.
In the research, Steckl and UC doctoral student Duk Young Kim demonstrated that paper could be used as a flexible host material for an electrowetting device. Electrowetting (EW) involves applying an electric field to colored droplets within a display in order to reveal content such as type, photographs and video. Steckl’s discovery that paper could be used as the host material has far-reaching implications considering other popular e-readers on the market such as the Kindle and iPad rely on complex circuitry printed over a rigid glass substrate.
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| Andrew Steckl’s research is featured on the cover of the November issue of ACS Applied Materials & Interfaces. The American Chemical Society (ACS) is the world’s largest scientific society. |
“One of the main goals of e-paper is to replicate the look and feel of actual ink on paper,” the researchers stated in the ACS article. “We have, therefore, investigated the use of paper as the perfect substrate for EW devices to accomplish e-paper on paper.”
Importantly, they found that the performance of the electrowetting device on paper is equivalent to that of glass, which is the gold standard in the field.
“It is pretty exciting,” said Steckl. “With the right paper, the right process and the right device fabrication technique, you can get results that are as good as you would get on glass, and our results are good enough for a video-style e-reader.”
Steckl imagines a future device that is rollable, feels like paper yet delivers books, news and even high-resolution color video in bright-light conditions.
“Nothing looks better than paper for reading,” said Steckl, an Ohio Eminent Scholar. “We hope to have something that would actually look like paper but behave like a computer monitor in terms of its ability to store information. We would have something that is very cheap, very fast, full-color and at the end of the day or the end of the week, you could pitch it into the trash.”
Disposing of a paper-based e-reader, Steckl points out, is also far simpler in terms of the environmental impact.
“In general, this is an elegant method for reducing device complexity and cost, resulting in one-time-use devices that can be totally disposed after use,” the researchers pointed out.
Steckl’s goal is attract commercial interest in the technology for next-stage development, which he expects will take three to five years to get to market.
The work was supported, in part, by a grant from the National Science Foundation and was conducted at the Nanoelectronics Laboratory at the University of Cincinnati College of Engineering and Applied Science.
Reference Link
http://www.uc.edu/news/NR.aspx?id=12779
Courtesy
University of Cincinnati
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