Related Experiment Video
Updated: Aug 2, 2025

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Majorization Theory for Unitary Control of Optical Absorption and Emission
1Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
Abstract:
Unitary control changes the absorption and emission of an object by transforming the external light modes. It is widely used and underlies coherent perfect absorption. Yet two basic questions remain unanswered: For a given object under unitary control, what absorptivity α, emissivity e, and their contrast δ=e-α are attainable? How to obtain a given α, e, or δ? We answer both questions using the mathematics of majorization. We show that unitary control can achieve perfect violation or preservation of Kirchhoff's law in nonreciprocal objects, and uniform absorption or emission for any object.
Related Concept Videos
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent...
UV–Vis Spectroscopy: Molecular Electronic Transitions
UV–Vis Spectroscopy: Woodward–Fieser Rules
Molecular Spectroscopy: Absorption and Emission
IR Absorption Frequency: Delocalization
In IR...
Ultraviolet and Visible (UV–Vis) Spectroscopy: Overview

