Quantum Antenna Arrays
Iñigo Liberal, Richard W. Ziolkowski · 2022
As the sizes and operating time scales of devices continue to shrink, quantum effects are becoming critical and classical descriptions are no longer adequate to understand and accurately predict their electromagnetic responses. At the same time, it is expected that controlling quantum effects will enable the design of communications, computational, and sensing systems with performance characteristics beyond classical limits. The blurring of the classical-quantum boundary affords many pioneering opportunities for electromagnetic scientists and engineers. This chapter introduces the analysis, design, and applications of arrays of quantum emitters. It aims to help bridge the gap between the classical and quantum worlds. Overviews of macroscopic QED (quantum electrodynamics) and photon statistics set the stage for understanding the performance characteristics of linear quantum antenna arrays. Innovative nonclassical light sources with no classical counterparts are described that are facilitated by the quantum physics associated with correlations, coherence, and additional degrees of freedom. It is demonstrated that these quantum antennas arrays can be arranged to realize directionally entangled photon bunches and perfectly isotropic single-photon sources. Quantum antenna array technologies are discussed that could be potentially used to implement these systems. Future aspirations for this nascent field are shared.