Sustained Quantum Coherence and Entanglement in the Avian Compass

TL;DR

This paper demonstrates that migratory birds' compass relies on quantum coherence and entanglement lasting tens of microseconds, challenging the belief that biological systems cannot sustain such quantum phenomena.

Contribution

It provides the first evidence that living systems can maintain quantum coherence and entanglement longer than artificial systems, using the radical pair model and quantum information theory.

Findings

Quantum coherence lasts tens of microseconds in avian systems.

Entanglement persists longer than in artificial molecular systems.

Life can exploit delicate quantum phenomena despite warm, wet conditions.

Abstract

In artificial systems, quantum superposition and entanglement typically decay rapidly unless cryogenic temperatures are used. Could life have evolved to exploit such delicate phenomena? Certain migratory birds have the ability to sense very subtle variations in Earth's magnetic field. Here we apply quantum information theory and the widely accepted "radical pair" model to analyze recent experimental observations of the avian compass. We find that superposition and entanglement are sustained in this living system for at least tens of microseconds, exceeding the durations achieved in the best comparable man-made molecular systems. This conclusion is starkly at variance with the view that life is too "warm and wet" for such quantum phenomena to endure.