Reliability of Digitized Quantum Annealing and the Decay of Entanglement

Abstract A banged‐digital‐analog simulation of a quantum annealing protocol is performed in a two‐qubit nuclear magnetic resonance (NMR) quantum computer. The experimental simulation employs up to 235 Trotter steps, with more than 2000 gates (pulses), and a protocol success above 80% is obtained. Given the exquisite control of the NMR quantum computer, the simulation is also performed with different noise levels. Thus, the reliability of the quantum annealing process is is analyzed, and it is related to the level of entanglement produced during the protocol. Although the presence of entanglement is not a sufficient signature for a better‐than‐classical simulation, the level of entanglement achieved relates to the fidelity of the protocol.