SciPost Submission Page
Experimental QND measurements of complementarity on two-qubit states with IonQ and IBM Q quantum computers
by Nicolas Schwaller, Valeria Vento, Christophe Galland
|As Contributors:||Christophe Galland|
|Arxiv Link:||https://arxiv.org/abs/2105.06368v1 (pdf)|
|Date submitted:||2021-05-20 16:22|
|Submitted by:||Galland, Christophe|
|Submitted to:||SciPost Physics Core|
We report the experimental nondemolition measurement of coherence, predictability and concurrence on a system of two qubits. The quantum circuits proposed by De Melo et al. are implemented on IBM Q (superconducting circuit) and IonQ (trapped ion) quantum computers. Three criteria are used to compare the performance of the different machines on this task: measurement accuracy, nondemolition of the observable, and quantum state preparation. We find that the IonQ quantum computer provides constant state fidelity through the nondemolition process, outperforming IBM Q systems on which the fidelity consequently drops after the measurement. Our study compares the current performance of these two technologies at different stages of the nondemolition measurement of bipartite complementarity.
Submission & Refereeing History
You are currently on this page
Reports on this Submission
Anonymous Report 1 on 2021-6-4 (Invited Report)
1.- Use of cloud quantum computing services in different platforms: superconducting qubits (IBM-Q) and Trapped ions (IonQ).
1.- Preparation and characterization of Bell states in quantum hardware is a decade old.
2.- Poor motivation of the importance of quantities of interest.
3.- Goal of the paper is not met: the results superficially assess that one platform is slightly better than the other without any further details.
4.- Discussion about scalability of the platforms without any theory and/or figure to support it.
In this manuscript the authors perform a quantum computation to characterize the quality of Bell states prepared on two different quantum hardware platforms via cloud services.
The authors calculate the concurrence, visibility and predictability of various quantum states by performing Quantum Non Demolition (QND) measurements using additional qubits and circuitry.
They use these quantities to assess the performance of the quantum hardware and make a comparison between the two platforms.
Unfortunately I am unable to recommend this work for publication in SciPost Core.
The main reason for this decision is that the manuscript does not meet the expectations of the journal;
Bell state preparation and characterization is more than a decade old and there is a vast literature about measuring, characterizing and studying Bell states in several platforms (see 10.1126/science.1130886 and Phys. Rev. A 81, 062325 (2010) as two of the first articles about it), thus not addressing a new or unsolved problem of the field.
Moreover, the results of this work are a basic quantum device benchmark step performed in any quantum computing lab, therefore the manuscript does not provide new results that help advancing the field or increase our understanding about quantum state characterization.
Finally, the conclusion is mostly focus on the scalability of the platforms without providing any data to back the claims in the form of computation times, latency in interaction with the cloud service, calibration measurements, etc.