by Staff Writers
New Haven CT (SPX) Apr 19, 2014
Scientists at Yale have confirmed a 50-year-old, previously untested theoretical prediction in physics and improved the energy storage time of a quantum switch by several orders of magnitude. They report their results in the April 17 issue of the journal Nature.
High-quality quantum switches are essential for the development of quantum computers and the quantum internet - innovations that would offer vastly greater information processing power and speed than classical (digital) computers, as well as more secure information transmission.
"Fighting dissipation is one of the main goals in the development of quantum hardware," said Ioan Pop, a postdoctoral researcher in applied physics at Yale and lead author of the paper. "A quantum switch needs to act reversibly without losing any energy. Our result is very encouraging for the development of superconducting quantum bits acting as switches."
Superconducting quantum bits, or qubits, are artificial atoms that represent information in quantum systems. They also manipulate that information as they switch among states - such as "0," "1," or both simultaneously - under the influence of other qubits. But in switching states, they tend to lose energy, resulting in information loss.
In the Yale experiment, researchers demonstrated that a type of superconducting quantum bit can be immune to dissipation in presence of a quasiparticle - a microscopic entity that normally saps the energy of the qubit.
"We can engineer a system that is immune to quasiparticle dissipation," Pop said.
The researchers used an artificial fluxonium atom as their qubit.
The experiment confirms by direct measurement a theoretical prediction made by Nobel Prize-winning British physicist Brian Josephson in the 1960s, namely that quasiparticle dissipation should vanish under certain conditions. Josephson junctions are superconducting devices with properties well suited for building quantum processing systems.
The results open new frontiers in areas related to quantum information and quantum measurements, the researchers said, providing both a strategy for building dissipation-immune quantum systems and a specific new device that could be adapted for better measuring properties of quasiparticles and understanding their origin and dynamics.
The paper is titled "Coherent suppression of electromagnetic dissipation due to superconducting quasiparticles." Co-authors are Kurtis Geerlings, Gianluigi Catelani, Robert J. Schoelkopf, Leonid I. Glazman and Michel Devoret.
Understanding Time and Space
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.|