Coupling a qubit coherently to an ensemble is the basis for collective quantum memories. A driven quantum dot can deterministically excite low-energy collective modes of a nuclear spin ensemble in the presence of lattice strain. We propose to gate a quantum state transfer between this central electron and these low-energy excitations -- spin waves -- in the presence of a strong magnetic field, where the nuclear coherence time is long. We develop a microscopic theory capable of calculating the exact time evolution of the strained electron-nuclear system. With this, we evaluate the operation of quantum state storage and show that fidelities up to 90% can be reached with a modest nuclear polarisation of only 50%. These findings demonstrate that strain-enabled nuclear spin waves are a highly suitable candidate for quantum memory.
@article{arxiv.1904.11180,
title = {Collective quantum memory activated by a driven central spin},
author = {Emil V. Denning and Dorian A. Gangloff and Mete Atatüre and Jesper Mork and Claire Le Gall},
journal= {arXiv preprint arXiv:1904.11180},
year = {2019}
}