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arXiv · 2104.11235

Entanglement from tensor networks on a trapped-ion QCCD quantum computer

Michael Foss-Feig·Stephen Ragole·Andrew Potter·Joan Dreiling·Caroline Figgatt·John Gaebler·Alex Hall·Steven Moses·Juan Pino·Ben Spaun·Brian Neyenhuis·David Hayes
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Abstract

The ability to selectively measure, initialize, and reuse qubits during a quantum circuit enables a mapping of the spatial structure of certain tensor-network states onto the dynamics of quantum circuits, thereby achieving dramatic resource savings when using a quantum computer to simulate many-body systems with limited entanglement. We experimentally demonstrate a significant benefit of this approach to quantum simulation: In addition to all correlation functions, the entanglement structure of an infinite system -- specifically the half-chain entanglement spectrum -- is conveniently encoded within a small register of "bond qubits" and can be extracted with relative ease. Using a trapped-ion QCCD quantum computer equipped with selective mid-circuit measurement and reset, we quantitatively determine the near-critical entanglement entropy of a correlated spin chain directly in the thermodynamic limit and show that its phase transition becomes quickly resolved upon expanding the bond-qubit register.

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Michael Foss-Feig, Stephen Ragole, Andrew Potter, Joan Dreiling, Caroline Figgatt, John Gaebler, Alex Hall, Steven Moses, Juan Pino, Ben Spaun, Brian Neyenhuis, David Hayes. 2021-04-22. Entanglement from tensor networks on a trapped-ion QCCD quantum computer. https://doi.org/10.1103/physrevlett.128.150504

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