Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strong Spin-Orbit Interaction and Helical Hole States in Ge/Si Nanowires   We study theoretically the low-energy hole states of Ge/Si core/shell
nanowires. The low-energy valence band is quasidegenerate, formed by two
doublets of different orbital angular momenta, and can be controlled via the
relative shell thickness and via external fields. We find that direct (dipolar)
coupling to a moderate electric field leads to an unusually large spin-orbit
interaction of Rashba type on the order of meV which gives rise to pronounced
helical states enabling electrical spin control. The system allows for quantum
dots and spin qubits with energy levels that can vary from nearly zero to
several meV, depending on the relative shell thickness.

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The categories of this paper are: eess
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The categories of this paper are: math
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The categories of this paper are: mtrl-th
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
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The categories of this paper are: cmp-lg
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The categories of this paper are: alg-geom
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The categories of this paper are: chao-dyn
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The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: physics
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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-th
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The categories of this paper are: q-fin