New Article: Reliability of digitized quantum annealing and the decay of entanglement

In this new article we used our NMR quantum computer (only two qubits…), in collaboration with Frederico Brito (USP-SC), to simulate in a digital-analog way a quantum annealing process. We currently hold (as far as I know…) the record of Trotter steps (235) and gates (more than 2000) in a quantum simulation. Moreover, we were able to relate the quality of the computation with the amount of entanglement it generated. But don’t let this trick you: more entanglement does seem to relate with better computation quality, but it does not necessarily imply better-than-classical computation! See the plot and description below, and click here for the full article.

Computation Reliabilty. Experimental results for mean (time-average) success and fidelity (top panel) and maximum and mean entanglement (bottom panel), as a function of the applied magnetic field gradient. Classical algorithm is assumed to not suffer any kind of noise, as it is implemented in a classical computer.

Computation Reliabilty. Experimental results for mean
(time-average) success and fidelity (top panel) and maximum and mean
entanglement (bottom panel), as a function of the applied magnetic
field gradient. Classical algorithm is assumed to not suffer any kind
of noise, as it is implemented in a classical computer.

Title: Reliability of digitized quantum annealing and the decay of entanglement

Authors: John P. S. Peterson (CBPF), Roberto S. Sarthour (CBPF), Alexandre M. Souza (CBPF), Ivan S. Oliveira (CBPF), Frederico Brito (USP-SC), Fernando de Melo (CBPF)

Abstract: We performed a banged-digital-analog simulation of a quantum annealing protocol in a two-qubit Nuclear Magnetic Resonance (NMR) quantum computer. Our experimental simulation employed up to 235 Trotter steps, with more than 2000 gates (pulses), and we obtained a protocol success above 80%. Given the exquisite control of the NMR quantum computer, we performed the simulation with different noise levels. We thus analyzed the reliability of the quantum annealing process, and related it 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.

Advertisements

One thought on “New Article: Reliability of digitized quantum annealing and the decay of entanglement

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s