The rationality of radical pair mechanism in real biological systems

TL;DR

This paper compares the radical pair mechanism (RPM) and Ramsey-like models for magnetic sensing, showing RPM's practicality in biological conditions despite lower accuracy, and Ramsey's superior performance in laboratory settings with precise control.

Contribution

It provides a comparative analysis of RPM and Ramsey-like models under different conditions, highlighting RPM's suitability for biological systems.

Findings

RPM outperforms Ramsey-like model in vivo conditions.

Ramsey-like model is better under laboratory conditions with precise control.

RPM offers greater practicality despite lower accuracy.

Abstract

The radical pair mechanism (RPM) in the chemical magnetic compass model is considered to be one of the most promising candidates for the avian magnetic navigation, and quantum needle phenomenon further boosts the navigation precision to a new high level. It is well known that there are also a variety of methods in the field of magnetic field sensing in laboratory, e.g. Ramsey protocol of NV centers in diamond. Here, we compare the RPM model and Ramsey-like model under laboratory conditions and under in vivo conditions respectively. The results are both surprising and reasonable. Under laboratory conditions, if we have precise control over time and a reasonably accurate prior knowledge of the magnetic field direction, the Ramsey-like model will outperform the RPM model. However, when such information is unavailable, as under in vivo conditions, the RPM model stands out. The RPM model achieves greater practicality at the cost of reduced accuracy.