Tomography and state reconstruction with superconducting single-photon detectors

TL;DR

This paper demonstrates quantum state reconstruction using a superconducting nanowire detector with nonlinear response, enabling improved accuracy over traditional linear detectors for coherent and thermal states.

Contribution

It introduces a superconducting nanowire detector with tunable bias current for enhanced multiphoton response in quantum state reconstruction.

Findings

Superconducting nanowire detector outperforms linear detectors in state reconstruction.

Bias current tuning improves the accuracy of quantum state reconstruction.

Effective reconstruction of coherent and thermal states achieved.

Abstract

We perform quantum state reconstruction of coherent and thermal states with a detector which has an enhanced multiphoton response. The detector is based on superconducting nanowires, where the bias current sets the dependence of the click probability on the photon number; this bias current is used as tuning parameter in the state reconstruction. The nonlinear response makes our nanowire-based detector superior to the linear detectors that are conventionally used for quantum state reconstruction.