Experimental characterization of quantum dynamics through many-body interactions

TL;DR

This paper demonstrates an efficient quantum process tomography method using multi-body correlations in trapped ions, enabling rapid and complete characterization of single-qubit quantum dynamics with minimal experimental configurations.

Contribution

It introduces a generalized DCQD technique utilizing three ancilla qubits for comprehensive single-qubit process characterization with fewer measurements.

Findings

Measured T1 and T2 relaxation times with a single configuration.

Achieved complete process characterization using multi-body correlations.

Reduced experimental complexity compared to standard QPT.

Abstract

We report on the implementation of a quantum process tomography (QPT) technique known as direct characterization of quantum dynamics (DCQD) applied on coherent and incoherent single- qubit processes in a system of trapped calcium 40 ions. Using quantum correlations with an ancilla qubit, DCQD reduces exponentially the number of experimental configurations required for standard QPT. With this technique, the system's relaxation times T1 and T2 were measured with a single experimental configuration. We further show the first complete characterization of single-qubit processes using a single generalized measurement realized through multi-body correlations with three ancilla qubits.