Many animals use Earth’s magnetic field as an aid for navigation. For several species of birds the evidence points to a compass based on the quantum properties of the electronic spin . However, these compass spins will not only experience Earth’s magnetic field but must also interact strongly with the ‘hot and wet’ biological environment .
The precise workings of the birds' compass remain a topic of debate, but analysing data from behavioural studies already allows us to extract some of its surprising properties, and we have recently predicted world-record spin coherence times . Recent experimental studies confirm the extraordinary sensitivity of the bird’s compass to tiny electromagnetic field fluctuations [3, 4], and thus underline the need for a better theoretical understanding of this biological quantum system.
In this project you will be developing theoretical models of the physical properties of a radical pair of spins in a condensed matter environment. This will be accomplished by applying and developing non-Markovian open quantum systems techniques. The goal of this project will be to understand how the exceptionally long-lived quantum coherence may survive in the messy physical environment surrounding the core compass unit, and to develop experimentally testable predictions.
References and further reading:
 A model for photoreceptor-based magnetoreception in birds. Gauger et al., Schulten, Swenberg & Weller Z. Phys. Chem. 111, 1 (1978). Ritz, Adem & Schulten Biophys. J. 78, 707 (2000).
 Sustained Coherence and Entanglement in the Avian Compass. Gauger et al., Phys. Rev Lett. 106, 040503 (2011). Stoneham, Gauger et al., Biophys. J. 102, 961 (2012).
 Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird. Engels et al., Nature 509, 353 (2014).
 Magnetic orientation of garden warblers (Sylvia borin) under 1.4 MHz radiofrequency magnetic field. Kavokin et al., J. R. Soc. Interface 11, 20140451 (2014).
Please send inquiry emails to Dr. Erik Gauger at E.Gauger@hw.ac.uk