Sensitive magnetic compass in the presence of decohering nuclear environment

Theoretical studies indicating the presence of long-lived coherence in the avian compass system have engendered the question of sustained coherence in the realistic radical pair system. In this manuscript we investigate this question along with the study of coherence dynamics in these systems. We show, for a realistic compass system, the sustenance of long-lived coherence is highly unlikely and depends strongly on the interactions with the nuclear hyperfine environment. We also study the role of various hyperfine interactions on the coherence and compass sensitivity and establish hyperfine anisotropy as an essential quantity for sensitive functioning of the compass. Based on this study we propose a regime of compass parameters where it shows good sensitivity without having sustained coherence. This work weakens the role of sustained coherence in the functioning of the avian compass.