Repetitive Readout of a Single Electronic Spin via Quantum Logic with Nuclear Spin Ancillae
L. Jiang,1,*,
J. S. Hodges,1,2,*
J. R. Maze,1,*
P. Maurer,1
J. M. Taylor,3,
D. G. Cory,2
P. R. Hemmer,4
R. L. Walsworth,1,5
A. Yacoby,1
A. S. Zibrov,1
M. D. Lukin1,
Robust measurement of single quantum bits plays a key role in
the realization of quantum computation and communication as
well as in quantum metrology and sensing. We have implemented
a method for the improved readout of single electronic spin
qubits in solid-state systems. The method makes use of quantum
logic operations on a system consisting of a single electronic
spin and several proximal nuclear spin ancillae in order to
repetitively readout the state of the electronic spin. Using
coherent manipulation of a single nitrogen vacancy center in
room-temperature diamond, full quantum control of an electronic-nuclear
system consisting of up to three spins was achieved. We took
advantage of a single nuclear-spin memory in order to obtain
a 10-fold enhancement in the signal amplitude of the electronic
spin readout. We also present a two-level, concatenated procedure
to improve the readout by use of a pair of nuclear spin ancillae,
an important step toward the realization of robust quantum information
processors using electronic- and nuclear-spin qubits. Our technique
can be used to improve the sensitivity and speed of spin-based
nanoscale diamond magnetometers.
2 Department of Nuclear Science and Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
3 Department of Physics, MIT, Cambridge, MA 02139, USA.
4 Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA.
5 Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA.
* These authors contributed equally to this work.
Present address: Institute for Quantum Information, California Institute of Technology, Pasadena, CA 91125, USA.
Present address: Joint Quantum Institute, University of Maryland, College Park, MD 20742, USA.
To whom correspondence should be addressed. E-mail: lukin{at}fas.harvard.edu
