Dynamic control of spontaneous emission using magnetized InSb higher-order-mode antennas

Abstract

We exploit InSb’s magnetic-induced optical properties to design THz sub-wavelength antennas that actively tune the radiative decay rates of dipole emitters at their proximity. The proposed designs include a spherical InSb antenna and a cylindrical Si-InSb hybrid antenna demonstrating distinct behaviors. The former dramatically enhances both radiative and non-radiative decay rates in the epsilon-near-zero region due to the dominant contribution of the Zeeman-splitting electric octupole mode. The latter realizes significant radiative decay rate enhancement via magnetic octupole mode, mitigating the quenching process and accelerating the photon production rate. A deep-learning-based optimization of emitter positioning further enhances the quantum efficiency of the proposed hybrid system. These novel mechanisms are promising for tunable THz single-photon sources in integrated quantum networks.

Keywords

• active antenna
• indium antimonide (InSb)
• local density of states
• multipole moments
• radiative decay rate
• Zeeman-splitting effect