Submitted on January 1, 2008
Accepted on March 6, 2008
Coherent Dynamics of a Single Spin Interacting with an Adjustable Spin Bath
R. Hanson 1*, V. V. Dobrovitski 2, A. E. Feiguin 3, O. Gywat 3, D. D. Awschalom 3
1 California Nanosystems Institute, University of California, Santa Barbara, CA 93106 USA.; Present address: Kavli Institute of Nanoscience Delft, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands.
2 Ames Laboratory and Iowa State University, Ames, IA 50014, USA.
3 California Nanosystems Institute, University of California, Santa Barbara, CA 93106 USA.
* To whom correspondence should be addressed.
R. Hanson , E-mail: r.hanson{at}tudelft.nl
Phase coherence is a fundamental concept in quantum mechanics. Understanding loss of coherence is paramount for future quantum information processing. We study the coherent dynamics of a single, central spin (a nitrogen-vacancy center) coupled to a bath of spins (nitrogen impurities) in diamond. Our experiments show that both the internal interactions of the bath and the coupling between the central spin and the bath can be tuned in situ, allowing access to regimes with surprisingly different behavior. The observed dynamics are well explained by analytics and numerical simulations, leading to valuable insight into loss of coherence in spin systems. These measurements demonstrate that spins in diamond provide an excellent testbed for models and protocols in quantum information.
