Biological measurement beyond the quantum limit

TL;DR

This paper demonstrates surpassing the quantum noise limit in biological measurements using non-classically correlated light, enabling more sensitive and faster microrheology within living cells.

Contribution

It introduces a method to exceed the quantum limit in biological optical measurements using quantum-enhanced techniques, specifically in microrheology within yeast cells.

Findings

Achieved 2.4 dB sensitivity improvement beyond the quantum noise limit.

Enhanced measurement rate of 64% for cytoplasm viscoelastic properties.

Paves the way for broader application of quantum resources in biology.

Abstract

Quantum noise places a fundamental limit on the per photon sensitivity attainable in optical measurements. This limit is of particular importance in biological measurements, where the optical power must be constrained to avoid damage to the specimen. By using non-classically correlated light, we demonstrated that the quantum limit can be surpassed in biological measurements. Quantum enhanced microrheology was performed within yeast cells by tracking naturally occurring lipid granules with sensitivity 2.4 dB beyond the quantum noise limit. The viscoelastic properties of the cytoplasm could thereby be determined with a 64% improved measurement rate. This demonstration paves the way to apply quantum resources broadly in a biological context.