Shrinking Photons Down to the Near-atomic Scale: Controlling Forbidden Transitions, Developing New Two-photon Sources, and Enabling Nano-photonics at Gamma-ray Frequencies

Nicholas Rivera, Massachusetts Institute of Technology

The past two decades have seen a great surge of interest in nanophotonics: the control of electromagnetic fields on length-scales of less than 1 micron. But only recently have theoretical and experimental methods been put forth for realizing "true" nanophotonics: control over fields on length scales as small as 10 nm. In this work, we examine the consequences of such confined fields on fundamental interactions between light and matter. We do so by developing a relativistic theory of quantum electrodynamics applicable to the interaction of external charges (such as excited atoms or free electrons) with arbitrary continuous media. Through the theoretical methods developed here, we find that a number of new possibilities arise with such confined fields, such as accessing and controlling conventionally forbidden radiation processes in atomic systems, controlling electronic transitions using the orbital symmetry of light, developing highly efficient sources of photon pairs, the development of spontaneous and stimulated emitters of light at gamma-ray frequencies, and the ability to access regimes of light emission where the quantum behavior of electrons becomes evident.

Abstract Author(s): Nicholas Rivera, Francisco Machado, Bo Zhen, Liang Jie Wong, Hrvoje Buljan, John D. Joannopoulos, Ido Kaminer, Marin Soljacic.