Quantum Tomography of Rydberg Atom Graphs by Configurable Ancillas

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 that use tomo-graphically orthogonal base measurements require precise and individual qubit controls, which are often experimentally daunting. Here we propose, as a quantum mechanically robust alternative, using configurable ancillas, the continuously tunable interactions of which can generate independent base measurements tomographically sufficient for the quantum state reconstruction of the system of inter-est. Experimental tests are performed for Rydberg atom arrays in N-body W states, the results of which demonstrate reliable high-fidelity full quantum state reconstruction by the proposed method.