Resonant weak-value enhancement for solid-state quantum metrology

TL;DR

This paper proposes a solid-state quantum metrology method using resonant weak-value amplification in a spintronic device, achieving high sensitivity for detecting weak Zeeman effects with enhanced quantum Fisher information.

Contribution

It introduces a novel solid-state platform employing resonant tunneling and weak-value amplification for ultra-sensitive parameter estimation in quantum metrology.

Findings

Quantum Fisher information enhanced by 10^4 times

High sensitivity maintained despite dephasing effects

Potential for detecting small Zeeman effects in quantum materials

Abstract

Quantum metrology that employs weak-values can potentially effectuate parameter estimation with an ultra-high sensitivity and has been typically explored across quantum optics setups. Recognizing the importance of sensitive parameter estimation in the solid-state, we propose a spintronic device platform to realize this. The setup estimates a very weak localized Zeeman splitting by exploiting a resonant tunneling enhanced magnetoresistance readout. We establish that this paradigm offers nearly optimal performance with a quantum Fisher information enhancement of about $10^4$ times that of single high-transmissivity barriers. The obtained signal also offers a high sensitivity in the presence of dephasing effects typically encountered in the solid state. These results put forth definitive possibilities in harnessing the inherent sensitivity of resonant tunneling for solid-state quantum metrology with potential applications, especially, in the sensitive detection of small induced Zeeman effects in quantum material heterostructures.