Phonon mediated spin relaxation in a moving quantum dot
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2015-03-03 |
| Journal | Bulletin of the American Physical Society |
| Authors | Xinyu Zhao, Peihao Huang, Xuedong Hu |
Abstract
Section titled āAbstractāThe allure of ultra-powerful quantum computers has pushed for ever more precise knowledge of quantum coherent dynamics in semiconductor and superconductor nanostructures. The acquired understanding may also lead to technological applications now, as best illustrated by extremely sensitive magnetic field sensors made from Nitrogen-Vacancy centers in diamond. Here we study an electron spin qubit confined in a moving quantum dot (QD), with our attention on both spin relaxation, and the product of spin relaxation, the emitted phonons. We find that Doppler effect leads to several interesting phenomena. From the perspective of spin relaxation, its rate peaks when the QD motion is in the transonic regime, which we term a spin relaxation boom in analogy to the classical sonic boom. This peak indicates that a moving spin qubit may have even lower relaxation rate than a static qubit, pointing at the possibility of coherence-preserving transport for a spin qubit. From the perspective of the emitted phonons, we find that the phonons becomes strongly directional and narrow in their frequency range as the qubit reaches the supersonic regime, similar to Cherenkov radiation. Thus fast moving excited spin qubits can act as a source of non-classical phonons. Taking together, these results have important implications to both spin-based quantum information processing and coherent phonon optics.
Tech Support
Section titled āTech SupportāOriginal Source
Section titled āOriginal Sourceā- DOI: None