Surface ESR response of a topological insulator nanoribbon

We consider the electron spin resonance dissipative response of the surface states of a topological insulator nanoribbon embedded in a cavity with a static magnetic field applied in parallel to the nanoribbon When driven by a second GHz range magnetic field perpendicular to the nanoribbon we predict that huge orbital resonances can be generated reflected in periodic changes of the Q factor of the cavity as function of the static magnetic field We show that this effect is unique to topological insulators and that it probes the interplay between the spin and angular momentum textures of the surface states as well as the peculiar flow of levels as function of the static magnetic field