Temperature-dependent terahertz magnetic dipole radiation from antiferromagnetic GdFeO3 ceramics

Temperature-dependent terahertz magnetic dipole radiation in antiferromagnetic GdFeO3 ceramic is investigated both theoretically and experimentally in this work. A two-level quantum transition mechanism is introduced to describe the excitation-radiation process, and radiative lifetime is derived analytically from the change of spin state density during this process. Terahertz spectral measurements demonstrate that the radiative frequency exhibits a red-shift and lifetime shortens as temperature increases, which is in good agreement with theoretical predictions. The temperature-sensitive radiative frequency and excellent terahertz emission mean that the antiferromagnetic ceramics show potential for application in terahertz sensors and frequency-tunable terahertz lasers. (C) 2013 AIP Publishing LLC.