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arXiv · 2403.12779

Quantum Fisher information in a strange metal

Federico Mazza·Sounak Biswas·Xinlin Yan·Andrey Prokofiev·Paul Steffens·Qimiao Si·Fakher F. Assaad·Silke Paschen
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Abstract

A strange metal is an exotic state of correlated quantum matter; intensive efforts are ongoing to decipher its nature. Here we explore whether the quantum Fisher information (QFI), a concept from quantum metrology, can provide new insight. We use inelastic neutron scattering and quantum Monte Carlo simulations to study a Kondo destruction quantum critical point, where strange metallicity is associated with fluctuations beyond a Landau order parameter. We find that the QFI probed away from magnetic Bragg peaks, where the effect of magnetic ordering is minimized, increases strongly and without a characteristic scale as the strange metal forms with decreasing temperature, evidencing its unusual entanglement properties. Our work opens a new direction for studies across strange metal platforms.

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Federico Mazza, Sounak Biswas, Xinlin Yan, Andrey Prokofiev, Paul Steffens, Qimiao Si, Fakher F. Assaad, Silke Paschen. 2024-03-19. Quantum Fisher information in a strange metal. https://doi.org/10.1038/s41567-026-03298-0

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