Kun Meng, Linyan Nie, Johannes Berger, Nick R. von Grafenstein, Stefan Weber, Lars-Oliver Essen, Roberto Rizzato, Christopher Einholz, Erik Schleicher, Dominik B. Bucher
Optically addressable spin systems have been widely studied for quantum-sensing applications. In this work, we demonstrate that photogenerated spin-correlated radical pairs in certain flavoproteins, cryptochrome and improved light-oxygen-voltage protein, can be manipulated by radio waves. This capability enables magnetic field sensing and spatial modulation of photoluminescence using radiofrequency pulses and magnetic field gradients, establishing proteins as a platform for optically addressable spin systems and radiofrequency-based control of biological processes.