Coherent control to prepare an InAs quantum dot for spin-photon entanglement.
We optically generated an electronic state in a single InAs/GaAs self-assembled quantum dot that is a precursor to the deterministic entanglement of the spin of the electron with an emitted photon in the proposal of W. Yao, R.-B. Liu, and L. J. Sham [Phys. Rev. Lett. 95, 030504 (2005). A superposition state is prepared by optical pumping to a pure state followed by an initial pulse. By modulating the subsequent pulse arrival times and precisely controlling them using interferometric measurement of path length differences, we are able to implement a coherent control technique to selectively drive exactly one of the two components of the superposition to the ground state. This optical transition contingent on spin was driven with the same broadband pulses that created the superposition through the use of a two pulse coherent control sequence. A final pulse affords measurement of the coherence of this "preentangled" state.
The H. M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109, USA.
L A
LA
Webster
The H. M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109, USA.
K
K
Truex
The H. M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109, USA.
L-M
LM
Duan
The H. M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109, USA.
D G
DG
Steel
The Naval Research Laboratory, Washington D.C. 20375, USA.
A S
AS
Bracker
The Naval Research Laboratory, Washington D.C. 20375, USA.
D
D
Gammon
Department of Physics, University of California, San Diego, La Jolla, California 92093-0319, USA.
L J
LJ
Sham