Quantum tomography of Rydberg atom graphs by configurable ancillas

TL;DR

This paper introduces a robust quantum tomography method using configurable ancillas with tunable interactions, enabling high-fidelity reconstruction of Rydberg atom states without requiring precise individual qubit control.

Contribution

It presents a novel ancilla-based approach for quantum state tomography that simplifies experimental requirements for many-body systems.

Findings

Successfully reconstructed N-body W states with high fidelity.

Demonstrated robustness against experimental imperfections.

Validated method on Rydberg atom arrays.

Abstract

Tomographic reconstruction of the many-body quantum state of a scalable qubit system is of paramount importance in quantum computing technologies. However, conventional approaches which use tomographically orthogonal base measurements require precise and individual qubit controls which are often experimentally daunting. Here, we propose, as a quantum-mechanically robust alternative, to use configurable ancillas of which the continuously-tunable interactions can generate independent base measurements tomographically sufficient for the quantum state reconstruction of the system of interest. Experimental tests are performed for Rydberg atom arrays in $N$-body $W$ states, of which the results demonstrate reliable high-fidelity full quantum state reconstruction of the proposed method.