Southwest Quantum Information and Technology

Coherence properties of donor-bound electron spins in ZnO

Presenting Author: Maria Viitaniemi, University of Washington
Contributing Author(s): Xiayu Linpeng, Y. Kozuka, Cameron Johnson, Joseph Falson, Atsushi Tsukazaki, M. Kawasaki, and Kai-Mei Fu

Donor impurities in ZnO may be a promising solid state qubit candidate for photon-mediated quantum networks. Efficient and homogeneous transitions allow for optical control of the electron spin state. Long spin coherence times and strong donor nucleus-electron interactions show promise for incorporation into future quantum information processors. Here we demonstrate coherent control of the Ga donor in ZnO over small angles and present ensemble measurements of optical pumping, T1, T2* and T2. We find that T1 exceeds ~0.1 s at 2.5 T with a B^-3.5 dependence. We thus expect T1 to exceed 1s at fields less than 1 T. Measurements of ~20ns for T2* and ~30μs for the spin echo decoherence time (T2) are also described. We will discuss possible limitations on T2 including instantaneous spectral diffusion of donors (n~10^17 cm^-3) and Zn67 nuclear spins (4.1% of natural Zn). Through isotope purification and single donor isolation, we believe we will be able to significantly increase the spin coherence time. Funding acknowledgement: This material is based upon work supported by the National Science Foundation under Grant No. 1150647. K.M. F. also acknowledges the support from the Research Corporation for Science Advancement as a Cottrell Scholar.

(Session 5 : Thursday from 5:00pm - 7:00 pm)