Shining a light on quantum bits

first_img Researchers create quantum calculator Quantum computing, no cooling required In the world of quantum computing, interaction is everything.For computers to work at all, bits — the ones and zeros that make up digital information — must be able to interact and hand off data for processing. The same goes for the quantum bits, or qubits, that make up quantum computers.But that interaction creates a problem — in any system in which qubits interact with each other, they also tend to want to interact with their environment, resulting in qubits that quickly lose their quantum nature.To get around the problem, Graduate School of Arts and Sciences Ph.D. student Ruffin Evans turned to particles mostly known for their lack of interactions — photons. This research was supported with funding from the NSF, the CUA, the DoD/ARO DURIP program, the AFOSR MURI, the ONR MURI, the ARL, the Vannevar Bush Faculty Fellowship program, the DoD NDSEG, and the NSF GRFP. Scientists coax photons to bind into molecules for first time New system could shed light on a host of complex processes center_img Working in the lab of Mikhail Lukin, the George Vasmer Leverett Professor of Physics and co-director of the Quantum Science and Engineering Initiative, Evans is lead author of a study, described in the journal Science, that demonstrates a method for engineering an interaction between two qubits using photons.“It’s not hard to engineer a system with very strong interactions, but strong interactions can also cause noise and interference through interaction with the environment,” Evans said. “So you have to make the environment extremely clean. This is a huge challenge. We are operating in a completely different regime. We use photons, which have weak interactions with everything.”Evans and colleagues began by creating two qubits using silicon-vacancy centers — atomic-scale impurities in diamonds — and putting them inside a nano-scale device known as a photonic crystal cavity, which behaves like two facing mirrors.“The chance that light interacts with an atom in a single pass might be very, very small, but once the light bounces around 10,000 times, it will almost certainly happen,” he said. “So one of the atoms can emit a photon, and it will bounce around between these mirrors, and at some point, the other atom will absorb the photon.”The transfer of that photon doesn’t go only one way, though.“The photon is actually exchanged several times between the two qubits,” Evans said. “It’s like they’re playing hot potato; the qubits pass it back and forth.”Piecing together the process: The microscope objective (the big metallic barrel coming down from the top of the image), the diamond sample (the small plate that looks like glass in the center of the image), and the optical fiber that couples to the sample (glowing green point just above the sample). Credit: Denis SukachevWhile the notion of creating interaction between qubits isn’t new — researchers have managed the feat in a number of other systems — there are two factors that make the new study unique, Evans said.“The key advance is that we are operating with photons at optical frequencies, which are usually very weakly interacting,” he said. “That’s exactly why we use fiber optics to transmit data — you can send light through a long fiber with basically no attenuation. So our platform is especially exciting for long-distance quantum computing or quantum networking.”And though the system operates only at ultra-low temperatures, Evans said it is less complex than approaches that require elaborate systems of laser cooling and optical traps to hold atoms in place. Because the system is built at the nano scale, he added, it opens the possibility that many devices could be housed on a single chip.“Even though this sort of interaction has been realized before, it hasn’t been realized in solid-state systems in the optical domain,” he said. “Our devices are built using semiconductor fabrication techniques. It’s easy to imagine using these tools to scale up to many more devices on a single chip.”Evans envisions two main directions for future research. The first involves developing ways to exert control over the qubits and building a full suite of quantum gates that would allow them to function as a workable quantum computer.“The other direction is to say we can already build these devices, and take information, read it out of the device and put it in an optical fiber, so let’s think about how we scale this up and actually build a real quantum network over human-scale distances,” he said. “We’re envisioning schemes to build links between devices across the lab or across campus using the ingredients we already have, or using next-generation devices to realize a small-scale quantum network.”Ultimately, Evans said, the work could have wide-reaching impacts on the future of computing.“Everything from a quantum internet to quantum data centers will require optical links between quantum systems, and that’s the piece of the puzzle that our work is very well-suited for,” he said.In addition to Evans and Lukin, the study represented a collaboration with Marko Loncar, the Tiantsai Lin Professor of Electrical Engineering, and Hongkun Park, the Mark Hyman, Jr. Professor of Chemistry and Professor of Physics.“We feel that these kinds of collaborations will create a backbone of the new Harvard Quantum Initiative for Science and Engineering,” Lukin said. Related Seeing light in a new way Harvard researchers create room-temperature quantum bits that store data for nearly two seconds last_img read more

Security Predictions for 2013

first_imgIt’s that time of year again when I make my bold (“somewhat safe” depending on your point of view) predictions about IT security for the upcoming year – 2013.The French journalist, novelist and social commentator, Jean-Baptiste Alphonse Karr, is the author of the witty expression, “plus ça change, plus c’est la même chose” which, as is almost always the case, sounds much more melodic than the English, “the more things change, the more they stay the same.” In reviewing my prior years’ prognostications, that phrase immediately popped into my head. How not to be repetitious when we face many of the same challenges?I am not sure I can because:1. The hackers will likely get even more sophisticated.Evidence of criminals collaborating with rogue nation states, exchanging methodologies, buying and selling information, and even subcontracting their respective capabilities expands their collective reach and enhances their mutual learning curves.2. Our attack surfaces will continue to expand and any remaining semblance of a perimeter will continue to wither away.Both will surely happen.My EMC colleague, Chuck Hollis, in his set of themes for 2013 says that next year organizations will come to terms with the pervasiveness of mobility and start to catch up on the offering of services to their users. Bingo. Wider attack surfaces. In addition, and somewhat needless to say, but I’ll say it anyway – the slow but steady march to cloud-oriented services will once again expand attack surfaces at the expense of the perimeter.This all leads me to my next moments of déjà vu which include:3. These changes will occur whether security teams are ready or not.In too many cases, not. There is a critical skills shortage of security professionals and many organizations can’t keep up.4. And, national governments will continue to diddle or, should I say, fiddle (while Rome burns), failing to legislate on rules of evidence, information sharing and the reforming of privacy laws.Lack of privacy reform is particularly troublesome based on today’s realities because many organizations have literally been put in the position of violating one set of privacy laws if they take the necessary steps to protect information (which they are legally obligated to do based on another set of privacy laws). Confused? So am I, but how would you like to be confused – and liable?I abhor the phrase “Cyber Pearl Harbor” because I think it is a poor metaphor to describe the state I believe we are in. However, I genuinely believe we are only a whisker away from some form of lesser catastrophic event that could do damage to the world economy or critical infrastructure.5. It is highly likely that a rogue nation state, hacktivists or even terrorists will move beyond intrusion and espionage to attempt meaningful disruption and, eventually, even destruction of critical infrastructure.If all of this sounds depressing, well, it is. This isn’t fear mongering. It is a plausible extrapolation from the facts. But we can change the trajectory. There is already a tectonic shift underway from a perimeter to an intelligence-based security model.In an age where breaches are probable, if not inevitable, organizations are realizing that static, siloed, perimeter defenses are ineffective against the evolving threat landscape. Only an intelligence-based model that is risk-oriented and situationally-aware can be resilient enough to minimize or eliminate the effects of attacks.So, now comes the good news:6. Responsible people in organizations from all verticals, industries and governments will move to that newer intelligence-based security model and pressure governments to act on our collective behalf.7. I also predict a significant uptake in investment for cloud-oriented security services to mitigate the effects of that serious shortage in cyber security skills.8. Big Data analytics will be used to enable an intelligence-based security model.Big Data will transform security enabling true defense in depth against a highly advanced threat environment.One final note. If we want to avoid going over the “security” cliff and really want change we can believe in, we must act more collaboratively and decisively than ever before. The stakes are getting too high for us to wait another year.This post originally appeared on on December 7, 2012.last_img read more

Video: Yvon Chouinard’s Favorite Energy Food

first_imgPatagonia plans to do for food what they’ve done for apparel — put people and the environment first, not profits. Here, Patagonia founder Yvon Chouinard explains the concept and tells the secret of his favorite energy food, Tsampa.last_img