Ultrafast optical spin echo for electron spins in semiconductors.
Spin-based quantum computing and magnetic resonance techniques rely on the ability to measure the coherence time T(2) of a spin system. We report on the experimental implementation of all-optical spin echo to determine the T(2) time of a semiconductor electron-spin system. We use three ultrafast optical pulses to rotate spins an arbitrary angle and measure an echo signal as the time between pulses is lengthened. Unlike previous spin-echo techniques using microwaves, ultrafast optical pulses allow clean T(2) measurements of systems with dephasing times (T_{2};{*}) fast in comparison to the time scale for microwave control. This demonstration provides a step toward ultrafast optical dynamic decoupling of spin-based qubits.
Clark
Susan M
SM
Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305-4088, USA. sclark4@stanford.edu
Fu
Kai-Mei C
KM
Zhang
Qiang
Q
Ladd
Thaddeus D
TD
Stanley
Colin
C
Yamamoto
Yoshihisa
Y