Theory of phonon-induced spin relaxation in a structured phononic reservoir
Abstract
By combining Markovian and non-Markovian open quantum system theory with finite-element simulations, we develop a theory of electron spin relaxation in a structured phononic reservoir. This problem is crucial for understanding spin dynamics in hybrid systems involving mechanical modes, as well as for the design of devices combining spin degrees of freedom with photonic and phononic architectures, where the phonon density of states is modulated in the relevant spectral range corresponding to moderate magnetic fields. Taking a QD in a phononic waveguide as a representative and technologically relevant example, we show that spin relaxation in such environments is much more complex than in bulk. While the relaxation rates are several times to an order of magnitude higher than in bulk, there are parameter windows where the relaxation is suppressed by many orders of magnitude due to gaps in mode dispersion and selection rules imposed by mode symmetry. At the border between these two sectors, van Hove singularities in phonon dispersion lead to singularities in relaxation rates, for which we develop power-law scaling and develop a non-Markovian description of the dynamics, revealing polaronic dressing of the spin into slow acoustic modes.
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BibTeX
@misc{haroon2026theory,
title = {{Theory of phonon-induced spin relaxation in a structured phononic reservoir}},
author = {Raseeb F. Haroon and Paweł Machnikowski},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2607.11479},
eprint = {2607.11479},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.11479},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Theory of phonon-induced spin relaxation in a structured phononic reservoir
AU - Raseeb F. Haroon
AU - Paweł Machnikowski
PY - 2026
DA - 2026/10/08
PB - arXiv
DO - 10.48550/arxiv.2607.11479
UR - https://arxiv.org/abs/2607.11479
AB - By combining Markovian and non-Markovian open quantum system theory with finite-element simulations, we develop a theory of electron spin relaxation in a structured phononic reservoir. This problem is crucial for understanding spin dynamics in hybrid systems involving mechanical modes, as well as for the design of devices combining spin degrees of freedom with photonic and phononic architectures, where the phonon density of states is modulated in the relevant spectral range corresponding to moderate magnetic fields. Taking a QD in a phononic waveguide as a representative and technologically relevant example, we show that spin relaxation in such environments is much more complex than in bulk. While the relaxation rates are several times to an order of magnitude higher than in bulk, there are parameter windows where the relaxation is suppressed by many orders of magnitude due to gaps in mode dispersion and selection rules imposed by mode symmetry. At the border between these two sectors, van Hove singularities in phonon dispersion lead to singularities in relaxation rates, for which we develop power-law scaling and develop a non-Markovian description of the dynamics, revealing polaronic dressing of the spin into slow acoustic modes.
ER -