Magnon-mediated quantum gates for superconducting qubits

Physical review. B./Physical review. B, vol. 110

Abstract

We propose a hybrid quantum system consisting of a magnetic particle inductively coupled to two superconducting transmon qubits, where qubit-qubit interactions are mediated via magnons. We show that the system can be tuned into three different regimes of effective qubit-qubit interactions, namely, a transverse ($XX+YY$), a longitudinal ($ZZ$), and a nontrivial $ZX$ interaction. In addition, we show that an enhanced coupling can be achieved by employing an ellipsoidal magnet, carrying anisotropic magnetic fluctuations. We propose a scheme for realizing two-qubit gates, and simulate their performance under realistic experimental conditions. We find that iswap and cz gates can be performed in this setup with an average fidelity $\ensuremath{\gtrsim}99%$, while an icnot gate can be applied with an average fidelity $\ensuremath{\gtrsim}88%$. Our proposed hybrid circuit architecture offers an alternative platform for realizing two-qubit gates between superconducting qubits and could be employed for constructing qubit networks using magnons as mediators.

Authors 6

1. Martijn Dols corresponding Aachen

   RWTH Aachen University · Delft University of Technology

   Affiliation as printed

   Delft University of Technology

   RWTH Aachen University

2. Sanchar Sharma

   Université Paris Cité · Université Paris Sciences et Lettres · École Normale Supérieure - PSL · Sorbonne Université · Laboratoire de Physique de l'Ecole Normale Supérieure

   Affiliation as printed

   ENS, Université PSL

   Laboratoire de Physique de l'École

   Sorbonne Université

   Université de Paris

3. Lenos Bechara Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University

4. Yaroslav M. Blanter

   Delft University of Technology

   Affiliation as printed

   Delft University of Technology

5. Marios Kounalakis Aachen

   Luxembourg Institute of Science and Technology · RWTH Aachen University · Delft University of Technology

   Affiliation as printed

   Delft University of Technology

   Luxembourg Institute of Science & Technology

   RWTH Aachen University

6. Silvia Viola Kusminskiy Aachen

   Max Planck Institute for the Science of Light · RWTH Aachen University

   Affiliation as printed

   Max Planck Institute for the Science of Light

   RWTH Aachen University