 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
| . |  |
. |
San Francisco CA (SPX) Sep 21, 2010 Finding ways to control matter at the level of single atoms and electrons fascinates many scientists and engineers because the ability to manipulate single charges and single magnetic moments (spins) may help researchers penetrate deep into the mysteries of quantum mechanics and modern solid-state physics. It may also allow development of new, highly sensitive magnetometers with nanometer resolution, single-spin transistors for coherent spintronics, and solid-state devices for quantum information processing. Recently, a collaboration of experimentalists from the Kavli Institute of Nanosciences at Delft University of Technology and theorists at the U.S. Department of Energy's Ames Laboratory made a breakthrough in the area of controlling single quantum spins. The researchers developed and implemented a special kind of quantum control over a single quantum magnetic moment (spin) of an atomic-sized impurity in diamond. These impurities, called nitrogen-vacancy (or N-V) centers, have attracted much attention due to their unusual magnetic and optical properties. But their fragile quantum states are easily destroyed by even miniscule interactions with the outside world. By applying a specially designed sequence of high-precision electromagnetic pulses, the scientists were able to protect the arbitrary quantum state of a single spin, and they made the spin evolve as if it was completely decoupled from the outside world. In this way, scientists achieved a 25-fold increase in the lifetime of the quantum spin state at room temperature. This is the first demonstration of a universal dynamical decoupling realized on a single solid state quantum spin. "Uncontrolled interactions of the spins with the environment have been the major hurdle for implementing quantum technologies" said the leader of Dutch experimental group, associate professor Ronald Hanson from Kavli Institute of Nanoscience at Delft. "Our results demonstrate that this hurdle can be overcome by advanced control of the spin itself." "Implementing dynamical decoupling on a single quantum spin in solid state at room temperature has been an appealing but distant goal for quite a while. In the meantime, much theoretical and experimental knowledge has been accumulated in the community," added Viatcheslav Dobrovitski, who led the theoretical research effort at the Ames Laboratory. "We used this knowledge to design our pulse sequences, and the collaboration between theory and experiment greatly helped us in this work." Besides its importance to fundamental understanding of quantum mechanics, the team's achievement opens a way to using the impurity centers in diamond as highly sensitive nanoscale magnetic sensors, and potentially, as qubits for larger-scale quantum information processing.
Share This Article With Planet Earth
Related Links Ames Laboratory Understanding Time and Space
Fundamental Constant Might Change Across SpaceLisbon, Portugal (SPX) Sep 07, 2010 New research suggests that the supposedly invariant fine-structure constant, which characterizes the strength of the electromagnetic force, varies from place to place throughout the Universe. The finding could mean rethinking the fundaments of our current knowledge of physics. These results will be presented tomorrow during the Joint European and National Astronomy Meeting in Lisbon, Portu ... read more |
|
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2010 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal 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 SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |
del.icio.us
Digg
Reddit
YahooMyWeb
Google
Facebook
