Basis-independent system-environment coherence is necessary to detect magnetic field direction in an avian-inspired quantum magnetic sensor

TL;DR

This paper demonstrates that basis-independent coherence in initial states is essential for optimal performance of an avian-inspired quantum magnetic sensor, highlighting its role as a quantum resource in biological systems.

Contribution

It introduces the concept that basis-independent coherence is necessary for biomolecular quantum sensors, expanding understanding of quantum effects in biological environments.

Findings

Basis-independent coherence is necessary for sensor performance.

Non-maximally mixed initial states are common in biomolecular scenarios.

A small degree of coherence is likely a quantum resource in biological systems.

Abstract

Advancing our understanding of non-trivial quantum effects in biomolecular complexes operating in physiological conditions requires the precise characterisation of the non-classicalities that may be present in such systems as well as asserting whether such features are required for robust function. Here we consider an avian-inspired quantum magnetic sensor composed of two radicals with a third "scavenger" radical under the influence of a collisional environment that allows to capture a variety of decoherence processes. We show that basis-independent coherence, in which the initial system-environment state is non-maximally mixed, is necessary for optimal performance of the quantum magnetic sensor, and appears to be sufficient in particular situations. We discuss how such non-maximally mixed initial states may be common for a variety of biomolecular scenarios. Our results therefore suggest that a small degree of coherence--regardless of basis--is likely to be a quantum resource for biomolecular systems operating at the interface between the quantum and classical domains.