Dual-Path Methods for Propagating Quantum Microwaves

Understand

We study quantum state tomography, entanglement detection, and channel noise reconstruction of propagating quantum microwaves via dual-path methods.

• The presented schemes make use of the following key elements: propagation channels, beam splitters, linear amplifiers, and field quadrature detectors.
• Remarkably, our methods are tolerant to the ubiquitous noise added to the signals by phase-insensitive microwave amplifiers.
• Furthermore, we analyze our techniques with numerical examples and experimental data, and compare them with the scheme developed in Eichler $et$ $al$ (2011 Phys.