Dr. Jianming Cai, Institut für Theoretische Physik
Abstract
Magnetic fields as weak as the Earth's may affect the outcome of certain photochemical reactions that go through a radical pair intermediate. The radical pair mechanism is one of the two main hypotheses to explain the navigability of animals in weak magnetic fields, enabling e.g. birds to see the Earth's magnetic field. It also plays an essential role in the field of spin chemistry. We study the dynamics of quantum entanglement and its role in this mechanism. We show how quantum control can be used to either enhance or reduce the performance of such a chemical compass, providing a new route to further study the radical pair mechanism and its applications. We further demonstrate how to optimize the design of a chemical compass with a much better directional sensitivity simply by a gradient field, which in the mean time can server as powerful tools to probe spin correlations in radical pair reactions.