Gyrotropic paramagnetic properties of Fe ions in a high-Q whispering gallery mode sapphire resonator

摘要

We report observations of the gyrotropic change in magnetic susceptibility of the Fe~(3+) electron paramagnetic resonance at 12.037GHz (between spin states |1/2> and |3/2>) in sapphire with respect to applied magnetic field. Measurements were made by observing the response of the high-Q Whispering Gallery doublet (WGH_(±17, 0, 0)) in a Hemex sapphire resonator cooled to 5 K. The doublets initially existed as standing waves at zero field and were transformed to traveling waves due to the gyrotropic response.