Tomography by noise

TL;DR

This paper introduces a simple, robust method for reconstructing photon number distributions using thermal noise as a probe, requiring minimal calibration and a single detector, demonstrated through experimental state inference.

Contribution

It presents a novel, efficient technique for quantum state tomography that uses thermal noise and minimal hardware, improving robustness and user-friendliness.

Findings

Successfully inferred single-photon, thermal, and two-photon states.

Method is stable against experimental imperfections.

Requires only one on/off detector and minimal calibration.

Abstract

We present an efficient and robust method for the reconstruction of photon number distributions by using solely thermal noise as a probe. The method uses a minimal number of pre-calibrated quantum devices, only one on/off single-photon detector is sufficient. Feasibility of the method is demonstrated by the experimental inference of single-photon, thermal and two-photon states. The method is stable to experimental imperfections and provides a direct, user-friendly quantum diagnostics tool.