Continuous and Reversible Electrical Tuning of Fluorescent Decay Rate via Fano Resonance

Abstract

We demonstrate that the decay rates of a fluorescent molecule can be controlled by electrically shifting a transparency introduced by a Fano resonance. An auxiliary quantum object (QO), located at the hotspot of a plasmonic nanoparticle, suppresses plasmonic excitation at its level spacing {\omega}_QO. As a result, the local density of states (LDOS) associated with the plasmonic spectrum is also suppressed at {\omega}={\omega}_QO. By shifting {\omega}_QO via an applied voltage, we continuously tune the radiative and nonradiative decay rates of the fluorescent molecule by up to two orders of magnitude. This mechanism offers a valuable tool for integrated quantum technologies, enabling on-demand entanglement and single-photon sources, voltage-controlled quantum gate operations, and electrical control of superradiant-like phase transitions. The approach also holds promise for applications in super-resolution microscopy and surface-enhanced Raman spectroscopy (SERS).