Submitted on May 19, 2009
Accepted on July 29, 2009
Repetitive Readout of a Single Electronic Spin via Quantum Logic with Nuclear Spin Ancillae
L. Jiang 1
, J. S. Hodges 2, J. R. Maze 1, P. Maurer 1, J. M. Taylor 3, D. G. Cory 4, P. R. Hemmer 5, R. L. Walsworth 6, A. Yacoby 1, A. S. Zibrov 1, M. D. Lukin 1*
1 Department of Physics, Harvard University,Cambridge, MA 02138, USA.
2 Department of Physics, Harvard University,Cambridge, MA 02138, USA.; Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
3 Department of Physics, Massachusetts Institute of Technology,Cambridge, MA 02139, USA.; Present address: Joint Quantum Institute, University of Maryland, College Park, MD, USA.
4 Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
5 Department of Electrical and Computer Engineering, Texas A&M University,College Station, TX 77843, USA.
6 Department of Physics, Harvard University,Cambridge, MA 02138, USA.; Harvard-Smithsonian Center for Astrophysics,Cambridge, MA 02138, USA.
* To whom correspondence should be addressed.
M. D. Lukin , E-mail: lukin{at}fas.harvard.edu
These authors contributed equally to this work.
Robust readout of single quantum information processors plays a key role in the realization of quantum computation and communication, as well as in quantum metrology and sensing. We implement a method for the improved readout of single spins in solid-state systems. We make use of quantum logic operations on a system composed of a single electronic spin and several proximal nuclear spin ancillae to repetitively readout the state of the electronic spin. Using coherent manipulation of a single nitrogen vacancy (NV) center in room temperature diamond, full quantum control of an electronic-nuclear system composed of up to three spins is demonstrated. We take advantage of a single nuclear spin memory to obtain a 10-fold enhancement in the signal amplitude of the electronic spin readout. Finally, we demonstrate a two-level, concatenated procedure to improve the readout using a pair of nuclear spin ancillae, representing an important step towards realization of robust quantum information processors using electronic and nuclear spin qubits. Our technique can be used to improve the sensitivity and the speed of spin-based nanoscale diamond magnetometers.
