{"205891":{"#nid":"205891","#data":{"type":"news","title":"Bose-Einstein Condensates Evaluated for Communicating Among Quantum Computers","body":[{"value":"\u003Cp\u003EQuantum computers promise to perform certain types of operations much more quickly than conventional digital computers. But many challenges must be addressed before these ultra-fast machines become available, among them, the loss of order in the systems \u2013 a problem known as quantum decoherence \u2013 which worsens as the number of bits in a quantum computer increases.\u003C\/p\u003E\u003Cp\u003EOne proposed solution is to divide the computing among multiple small quantum computers that would work together much as today\u2019s multi-core supercomputers team up to tackle big digital operations. The individual computers in such a system could communicate quantum information using Bose-Einstein condensates (BECs) \u2013 clouds of ultra-cold atoms that all exist in exactly the same quantum state. The approach could address the decoherence problem by reducing the number of bits necessary for a single computer.\u003C\/p\u003E\u003Cp\u003ENow, a team of physicists at the Georgia Institute of Technology has examined how this Bose-Einstein communication might work. The researchers determined the amount of time needed for quantum information to propagate across their BEC, essentially establishing the top speed at which such quantum computers could communicate.\u003C\/p\u003E\u003Cp\u003E\u201cWhat we did in this study was look at how this kind of quantum information would propagate,\u201d said \u003Ca href=\u0022https:\/\/www.physics.gatech.edu\/user\/chandra-raman\u0022\u003EChandra Raman\u003C\/a\u003E, an associate professor in Georgia Tech\u2019s \u003Ca href=\u0022https:\/\/www.physics.gatech.edu\/\u0022\u003ESchool of Physics\u003C\/a\u003E. \u201cWe are interested in the dynamics of this quantum information flow not just for quantum information systems, but also more generally for fundamental problems in physics.\u201d\u003C\/p\u003E\u003Cp\u003EThe research is scheduled to be published in the April 19 online version of the journal \u003Cem\u003EPhysical Review Letters\u003C\/em\u003E. The research was funded by the U.S. Department of Energy (DOE) and the National Science Foundation (NSF). The work involved both an experimental physics group headed by Raman and a theoretical physics group headed by associate professor Carlos Sa De Melo, also in the Georgia Tech School of Physics.\u003C\/p\u003E\u003Cp\u003EThe researchers first assembled a gaseous Bose-Einstein condensate that consisted of as many as three million sodium atoms cooled to nearly absolute zero. To begin the experiment, they switched on a magnetic field applied to the BEC that instantly placed the system out of equilibrium. That triggered spin-exchange collisions as the atoms attempted to transition from one ground state to a new one. Atoms near one another became entangled, pairing up with one atom\u2019s spin pointing up, and the other\u2019s pointing down. This pairing of opposite spins created a correlation between pairs of atoms that moved through the entire BEC as it established a new equilibrium.\u003C\/p\u003E\u003Cp\u003EThe researchers, who included graduate student Anshuman Vinit and former postdoctoral fellow Eva Bookjans, measured the correlations as they spread through the cloud of cold atoms. At first, the quantum entanglement was concentrated in space, but over time, it spread outward like drop of dye diffuses through water.\u003C\/p\u003E\u003Cp\u003E\u201cYou can imagine having a drop of dye that is concentrated at one point in space,\u201d Raman said. \u201cThrough diffusion, the dye molecules move throughout the water, slowly spreading throughout the entire system.\u201d\u003C\/p\u003E\u003Cp\u003EThe research could help scientists anticipate the operating speed for a quantum computing system composed of many cores communicating through a BEC.\u003C\/p\u003E\u003Cp\u003E\u201cThis propagation takes place on the time scale of ten to a hundred milliseconds,\u201d Raman said. \u201cThis is the speed at which quantum information naturally flows through this kind of system. If you were to use this medium for quantum communication, that would be its natural time scale, and that would set the timing for other processes.\u201d\u003C\/p\u003E\u003Cp\u003EThough relevant to communication of quantum information, the process also showed how a large system undergoing a phase transition does so in localized patches that expand to attempt to incorporate the entire system.\u003C\/p\u003E\u003Cp\u003E\u201cAn extended system doesn\u2019t move from one phase to another in a uniform way,\u201d said Raman. \u201cIt does this locally. Things happen locally that are not connected to one another initially, so you see this inhomogeneity.\u201d\u003C\/p\u003E\u003Cp\u003EBeyond quantum computing, the results may also have implications for quantum sensing \u2013 and for the study of other physical systems that undergo phase transitions.\u003C\/p\u003E\u003Cp\u003E\u201cPhase transitions have universal properties,\u201d Raman noted. \u201cYou can take the phase transitions that happen in a variety of systems and find that they are described by the same physics. It is a unifying principle.\u201d\u003C\/p\u003E\u003Cp\u003ERaman hopes the work will lead to new ways of thinking about quantum computing, regardless of its immediate practical use.\u003C\/p\u003E\u003Cp\u003E\u201cOne paradigm of quantum computing is to build a linear chain of as many trapped ions as possible and to simultaneously engineer away as many challenges as possible,\u201d he said. \u201cBut perhaps what may be successful is to build these smaller quantum systems that can communicate with one another. It\u2019s important to try as many things as possible and to keep an open mind. We need to try to understand these systems as well as we can.\u201d\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis research was supported by the Department of Energy (DOE) through grant DE-FG-02-03ER15450 and by the National Science Foundation under grant PHY-1100179. The conclusions in this article are those of the principal investigator and do not necessarily represent the official views of the DOE or the NSF.\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECITATION\u003C\/strong\u003E: Vinit, Anshuman, et al., \u201cAntiferromagnetic Spatial Ordering in a Quenched One-dimensional Spinor Gas, (Physical Review Letters, 2013).\u003Cbr \/\u003E\u003Cbr \/\u003E\u003Cstrong\u003EResearch News\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EGeorgia Institute of Technology\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003E177 North Avenue\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EAtlanta, Georgia\u0026nbsp; 30332-0181\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cbr \/\u003E\u003Cstrong\u003EMedia Relations Contact\u003C\/strong\u003E:\u0026nbsp; John Toon (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E)\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EPhysicists have examined how Bose-Einstein condensates (BEC) might be used to provide communication among the nodes of a distributed quantum computer. The researchers determined the amount of time needed for quantum information to propagate across their BEC.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Researchers are examining how Bose-Einstein condensates (BEC) might be used to communicate among quantum computers."}],"uid":"27303","created_gmt":"2013-04-11 13:04:57","changed_gmt":"2016-10-08 03:13:59","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2013-04-11T00:00:00-04:00","iso_date":"2013-04-11T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"205861":{"id":"205861","type":"image","title":"Bose-Einstein condensate in communication","body":null,"created":"1449179977","gmt_created":"2015-12-03 21:59:37","changed":"1475894861","gmt_changed":"2016-10-08 02:47:41","alt":"Bose-Einstein condensate in communication","file":{"fid":"196723","name":"bec-communication32.jpg","image_path":"\/sites\/default\/files\/images\/bec-communication32_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/bec-communication32_0.jpg","mime":"image\/jpeg","size":2192896,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/bec-communication32_0.jpg?itok=zJJkBZaU"}},"205871":{"id":"205871","type":"image","title":"Bose-Einstein condensate in communication2","body":null,"created":"1449179977","gmt_created":"2015-12-03 21:59:37","changed":"1475894861","gmt_changed":"2016-10-08 02:47:41","alt":"Bose-Einstein condensate in communication2","file":{"fid":"196724","name":"bec-communication71.jpg","image_path":"\/sites\/default\/files\/images\/bec-communication71_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/bec-communication71_0.jpg","mime":"image\/jpeg","size":1506154,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/bec-communication71_0.jpg?itok=0IGAA39u"}},"205881":{"id":"205881","type":"image","title":"Visualization quantum flow","body":null,"created":"1449179977","gmt_created":"2015-12-03 21:59:37","changed":"1475894861","gmt_changed":"2016-10-08 02:47:41","alt":"Visualization quantum flow","file":{"fid":"196725","name":"bec-localization.jpg","image_path":"\/sites\/default\/files\/images\/bec-localization_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/bec-localization_0.jpg","mime":"image\/jpeg","size":2814354,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/bec-localization_0.jpg?itok=FSIojOJa"}}},"media_ids":["205861","205871","205881"],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"7684","name":"Bose-Einstein"},{"id":"63761","name":"Bose-Einstein condensate"},{"id":"63771","name":"Chandra Raman"},{"id":"1744","name":"quantum"},{"id":"4359","name":"quantum computing"},{"id":"166937","name":"School of Physics"}],"core_research_areas":[{"id":"39431","name":"Data Engineering and Science"},{"id":"39481","name":"National Security"},{"id":"39541","name":"Systems"}],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EJohn Toon\u003C\/p\u003E\u003Cp\u003EResearch News\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E(404) 894-6986\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}