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arXiv · 2211.09567

Quantum Metrology Protected by Hilbert Space Fragmentation

Atsuki Yoshinaga·Yuichiro Matsuzaki·Ryusuke Hamazaki
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Abstract

We propose an entanglement-enhanced sensing scheme that is robust against spatially inhomogeneous always-on Ising interactions. Our strategy is to tailor coherent quantum dynamics employing the Hilbert-space fragmentation (HSF), a recently recognized mechanism that evades thermalization in kinetically constrained many-body systems. Specifically, we analytically show that the emergent HSF caused by strong Ising interactions enables us to design a stable state where part of the spins is effectively decoupled from the rest of the system. Using the decoupled spins as a probe to measure a transverse field, we demonstrate that the Heisenberg limited sensitivity is achieved without suffering from thermalization.

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Atsuki Yoshinaga, Yuichiro Matsuzaki, Ryusuke Hamazaki. 2022-11-17. Quantum Metrology Protected by Hilbert Space Fragmentation. https://arxiv.org/abs/2211.09567

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