%0 Journal Article
%T High-fidelity initialization of long-lived quantum dot hole spin qubits by reduced fine-structure splitting
%A Alistair J. Brash
%A Luis M. P. P. Martins
%A Feng Liu
%A John H. Quilter
%A Andrew J. Ramsay
%A Maurice S. Skolnick
%A Anthony M. Fox
%J Physics
%D 2015
%I arXiv
%R 10.1103/PhysRevB.92.121301
%X We demonstrate an on-demand hole spin qubit initialization scheme meeting four key requirements of quantum information processing: fast initialization (1/e ~ 100 ps), high fidelity (F > 99%), long qubit lifetime $(2T_{1}>T_{2}^{*}\simeq10\:\mathrm{ns})$, and compatibility with optical coherent control schemes. This is achieved by rapidly ionizing an exciton in an InGaAs quantum dot with very low fine-structure splitting at zero magnetic field. Furthermore, we show that the hole spin fidelity of an arbitrary quantum dot can be increased by optical Stark effect tuning of the fine-structure splitting close to zero.
%U http://arxiv.org/abs/1506.01736v2