SciPost logo

SciPost Submission Page

Fermionic quantum computation with Cooper pair splitters

by Kostas Vilkelis, Antonio Manesco, Juan Daniel Torres Luna, Sebastian Miles, Michael Wimmer, Anton Akhmerov

Submission summary

Authors (as registered SciPost users): Anton Akhmerov · Antonio Manesco · Juan Daniel Torres Luna · Kostas Vilkelis · Michael Wimmer
Submission information
Preprint Link: scipost_202404_00012v1  (pdf)
Code repository: https://doi.org/10.5281/zenodo.10838608
Date accepted: 2024-05-07
Date submitted: 2024-04-09 12:14
Submitted by: Vilkelis, Kostas
Submitted to: SciPost Physics
Ontological classification
Academic field: Physics
Specialties:
  • Condensed Matter Physics - Theory
  • Condensed Matter Physics - Computational
Approaches: Theoretical, Computational

Abstract

We propose a practical implementation of a universal quantum computer that uses local fermionic modes (LFM) rather than qubits. The device consists of quantum dots tunnel-coupled by a hybrid superconducting island and a tunable capacitive coupling between the dots. We show that coherent control of Cooper pair splitting, elastic cotunneling, and Coulomb interactions implements the universal set of quantum gates defined by Bravyi and Kitaev. Due to the similarity with charge qubits, we expect charge noise to be the main source of decoherence. For this reason, we also consider an alternative design where the quantum dots have tunable coupling to the superconductor. In this second device design, we show that there is a sweet spot for which the local fermionic modes are charge neutral, making the device insensitive to charge noise effects. Finally, we compare both designs and their experimental limitations and suggest future efforts to overcome them.

Author comments upon resubmission

We thank the referees for their feedback. We have replied to the referee reports directly and attached a redlined manuscript to the responses.

The summary of the main revisions is in the list of changes below.

List of changes

- Added a new section "Charge neutral local fermionic modes" that investigates charge neutral Andreev modes as local fermionic modes which are invariant under the effects of charge noise. Adjusted the abstract and summary according to the new findings.
- In a new Appendix C section, added additional time-dependent simulation plots for both charged and charge-neutral device proposals.
- Added a more systematic review of experimental references.
- In the "Introduction" section, added a short discussion of existing fermionic quantum computation proposals.
- Re-designed Figure 1 to clarify the meaning of the unit cell
- In the "Design" section, gave an additional explanation on the meaning of the $U_4$ gate.
- In the "Effective Hamiltonian" section, added an explanation on why both large charging energy and Zeeman splitting are required for charged local fermionic modes.
- Other small adjustments according to the request for changes outlined by the referees.

Current status:
Accepted in target Journal

Editorial decision: For Journal SciPost Physics: Publish
(status: Editorial decision fixed and (if required) accepted by authors)


Reports on this Submission

Anonymous Report 3 on 2024-4-22 (Invited Report)

Report

The authors have answered the questions I had in the first report, and they have made appropriate changes to the manuscript. In my opinion, this paper is now ready to be published.

Recommendation

Publish (easily meets expectations and criteria for this Journal; among top 50%)

  • validity: high
  • significance: good
  • originality: good
  • clarity: high
  • formatting: excellent
  • grammar: excellent

Anonymous Report 2 on 2024-4-20 (Invited Report)

Report

My comments have been appropriately addressed.

Recommendation

Publish (meets expectations and criteria for this Journal)

  • validity: -
  • significance: -
  • originality: -
  • clarity: -
  • formatting: -
  • grammar: -

Report 1 by Sergey Frolov on 2024-4-17 (Invited Report)

Report

I am okay with passing this paper through. I think I made my point and I am happy that my comment will be recorded publicly.

Recommendation

Publish (surpasses expectations and criteria for this Journal; among top 10%)

  • validity: -
  • significance: -
  • originality: -
  • clarity: -
  • formatting: -
  • grammar: -

Login to report or comment