Generalized overlap quantum state tomography

TL;DR

This paper introduces a resource-efficient quantum state tomography method that reconstructs the full density operator of arbitrary states using interference with calibrated coherent states and semidefinite programming, demonstrating robustness and physicality.

Contribution

It generalizes existing Wigner function reconstruction methods to efficiently and accurately reconstruct quantum states in the Fock basis without relying on approximate displacements.

Findings

Successfully demonstrated the protocol experimentally.

Achieved efficient and robust state reconstruction.

Ensured physicality of reconstructed states.

Abstract

We propose and experimentally demonstrate a quantum state tomography protocol that generalizes the Wallentowitz-Vogel-Banaszek-W\'odkiewicz point-by-point Wigner function reconstruction. The full density operator of an arbitrary quantum state is efficiently reconstructed in the Fock basis, using semidefinite programming, after interference with a small set of calibrated coherent states. This new protocol is resource- and computationally efficient, is robust against noise, does not rely on approximate state displacements, and ensures the physicality of results.