Superabsorption of light via quantum engineering

TL;DR

This paper demonstrates that quantum control techniques can enable superabsorption in nanostructures, allowing them to absorb light much faster than classical limits, with potential applications in energy harvesting and photon detection.

Contribution

It introduces a theoretical framework for achieving sustained superabsorption in simple nanostructures through quantum control, overcoming natural limitations.

Findings

Superabsorption can be achieved by trapping systems in highly excited states.

Energy can be extracted into non-radiative channels to sustain superabsorption.

Potential implementations include quantum dot arrays and porphyrin rings.

Abstract

Almost 60 years ago Dicke introduced the term superradiance to describe a signature quantum effect: N atoms can collectively emit light at a rate proportional to N^2. Even for moderate N this represents a significant increase over the prediction of classical physics, and the effect has found applications ranging from probing exciton delocalisation in biological systems, to developing a new class of laser, and even in astrophysics. Structures that super-radiate must also have enhanced absorption, but the former always dominates in natural systems. Here we show that modern quantum control techniques can overcome this restriction. Our theory establishes that superabsorption can be achieved and sustained in certain simple nanostructures, by trapping the system in a highly excited state while extracting energy into a non-radiative channel. The effect offers the prospect of a new class of quantum nanotechnology, capable of absorbing light many times faster than is currently possible; potential applications of this effect include light harvesting and photon detection. An array of quantum dots or a porphyrin ring could provide an implementation to demonstrate this effect.