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arXiv · 1606.07795

Quantum phase transition from bounded to extensive entanglement entropy in a frustration-free spin chain

Zhao Zhang·Amr Ahmadain·Israel Klich
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Abstract

We introduce a continuous family of frustration-free Hamiltonians with exactly solvable ground states. We prove that the {ground state of our model is non-degenerate and exhibits} a novel quantum phase transition from bounded entanglement entropy to a massively entangled state with volume entropy scaling. The ground state may be interpreted as a deformation away from the uniform superposition of colored Motzkin paths, showed by Movassagh and Shor to have a large (square-root) but sub-extensive scaling of entanglement into a state with an extensive entropy.

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Zhao Zhang, Amr Ahmadain, Israel Klich. 2016-06-24. Quantum phase transition from bounded to extensive entanglement entropy in a frustration-free spin chain. https://doi.org/10.1073/pnas.1702029114

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