Engineering Quantum Phenomena with Epsilon-Near-Zero (ENZ) Materials

Epsilon-near-zero (ENZ) materials have given rise to a rich variety of phenomena such as electromagnetic supercoupling, resonance pinning, perfect optical absorption, and ultrafast optical switching. In addition, ENZ materials have been successfully exploited to modulate the spontaneous emission intensity, including the spectrum and directionality, of quantum emitters. Here we present two additional phenomena that can arise as a result of ENZ materials interacting with quantum vacuum fluctuations. First, we will present the concept of electromagnetic bandgaps for nanoparticles comprising an ENZ material. The suppressed radiative emission is found to be invariant with respect to particle size and is therefore an intrinsic property of the ENZ material. Even for non-ideal ENZ materials (e.g., ITO), a suppression of ~90% is achieved within the bandgap region. Second, we will show how tunable ENZ materials can be used to convert electrical bias into mechanical motion through the Casimir force, resulting from a confinement of the quantum fluctuations of vacuum. Together, these effects show the potential of engineering quantum fluctuations through novel material systems for future device applications.