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arXiv · 2002.11823

Quantum Entangled Fractional Topology and Curvatures

Joel Hutchinson·Karyn Le Hur
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Abstract

We propose a two-spin quantum-mechanical model with applied magnetic fields acting on the Poincar\'e-Bloch sphere, to reveal a new class of topological energy bands with Chern number one half for each spin-1/2. The mechanism behind this fractional topology is a two-spin product state at the north pole and a maximally entangled state close to the south pole. The fractional Chern number of each spin can be measured through the magnetizations at the poles. We study a precise protocol where the spin dynamics in time reflects the Landau-Zener physics associated with energy band crossing effects. We show a correspondence between the two-spin system and topological bilayer models on a honeycomb lattice. These models describe semimetals with a nodal ring surrounding the region of entanglement.

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Joel Hutchinson, Karyn Le Hur. 2020-02-26. Quantum Entangled Fractional Topology and Curvatures. https://doi.org/10.1038/s42005-021-00641-0

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