High-spin magnetic ground states of neutral dopant clusters in semiconductors

Fuente: arXiv
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Main Authors: Samajdar, Rhine, Zhou, Haonan, Bhatt, R. N.
Format: Preprint
Published: 2025
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author Samajdar, Rhine
Zhou, Haonan
Bhatt, R. N.
author_facet Samajdar, Rhine
Zhou, Haonan
Bhatt, R. N.
contents High-spin states hold significant promise for classical and quantum information storage and emerging magnetic memory technologies. Here, we present a systematic framework for engineering such high-spin magnetic states in dopant clusters formed from substitutional impurities in semiconductors. In single-valley materials such as gallium arsenide, impurity states are hydrogenic and exchange interactions generally favor low-spin configurations, except in special geometries. In contrast, multivalley semiconductors exhibit oscillatory form factors in their exchange couplings, enabling the controlled suppression of selected hopping processes and exchange couplings. Exploiting this feature, we demonstrate how carefully arranged impurities in aluminum arsenide, germanium, and silicon can stabilize ground states with a net spin that scale extensively with system size. Within effective mass theory and the tight-binding approximation for hopping, we construct explicit examples ranging from finite clusters to extended lattices and fractal-like tilings. In two dimensions, we identify several favorable dopant geometries supporting a net spin equal to around half of the fully polarized value in the thermodynamic limit, including one which achieves over $70\%$ polarization. Our results provide a general design principle for harnessing valley degeneracy in semiconductors to construct robust high-spin states and outline a pathway for their experimental realization via precision implantation of dopants.
format Preprint
id arxiv_https___arxiv_org_abs_2510_03575
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle High-spin magnetic ground states of neutral dopant clusters in semiconductors
Samajdar, Rhine
Zhou, Haonan
Bhatt, R. N.
Mesoscale and Nanoscale Physics
Materials Science
Statistical Mechanics
Quantum Physics
High-spin states hold significant promise for classical and quantum information storage and emerging magnetic memory technologies. Here, we present a systematic framework for engineering such high-spin magnetic states in dopant clusters formed from substitutional impurities in semiconductors. In single-valley materials such as gallium arsenide, impurity states are hydrogenic and exchange interactions generally favor low-spin configurations, except in special geometries. In contrast, multivalley semiconductors exhibit oscillatory form factors in their exchange couplings, enabling the controlled suppression of selected hopping processes and exchange couplings. Exploiting this feature, we demonstrate how carefully arranged impurities in aluminum arsenide, germanium, and silicon can stabilize ground states with a net spin that scale extensively with system size. Within effective mass theory and the tight-binding approximation for hopping, we construct explicit examples ranging from finite clusters to extended lattices and fractal-like tilings. In two dimensions, we identify several favorable dopant geometries supporting a net spin equal to around half of the fully polarized value in the thermodynamic limit, including one which achieves over $70\%$ polarization. Our results provide a general design principle for harnessing valley degeneracy in semiconductors to construct robust high-spin states and outline a pathway for their experimental realization via precision implantation of dopants.
title High-spin magnetic ground states of neutral dopant clusters in semiconductors
topic Mesoscale and Nanoscale Physics
Materials Science
Statistical Mechanics
Quantum Physics
url https://arxiv.org/abs/2510.03575