The Heisenberg picture of photodetection

TL;DR

This paper develops Hamiltonian models for the entire photodetection process, from photon creation to macroscopic signal generation, using the Heisenberg picture to analyze single-photon detection analytically.

Contribution

It introduces a Hamiltonian framework for modeling the complete photodetection process, including photon absorption and amplification, with analytical solutions for simple cases.

Findings

Analytical description of single-photon detection in the Heisenberg picture

Separation of desirable and undesirable effects in the detection process

Framework extensible to more complex Hamiltonians

Abstract

We construct a class of Hamiltonians that describe the photodetection process from beginning to end. Our Hamiltonians describe the creation of a photon, how the photon travels to an absorber (such as a molecule), how the molecule absorbs the photon, and how the molecule after irreversibly changing its configuration triggers an amplification process---at a wavelength that may be very different from the photon's wavelength---thus producing a macroscopic signal. We use a simple prototype Hamiltonian to describe the single-photon detection process analytically in the Heisenberg picture, which neatly separates desirable from undesirable effects. Extensions to more complicated Hamiltonians are pointed out.