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Massive quantum superpositions using magnetomechanics

Sarath Raman Nair1,2,*,†, Shilu Tian3,*,‡, Gavin K. Brennen1,2, Sougato Bose4, and Jason Twamley3

  • *Joint first authors.
  • †Contact author: sarath.raman-nair@mq.edu.au
  • ‡Contact author: shilu.tian@oist.jp
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Phys. Rev. Applied 24, 024061 – Published 26 August, 2025

DOI: https://doi.org/10.1103/scnr-2rkt

Abstract

Macroscopic quantum superpositions of massive objects are very interesting as they have several potential applications, ranging from the exploration of the interaction of gravity with quantum mechanics to quantum sensing. In this article, we propose two related schemes to prepare a spatial superposition of massive quantum oscillator systems with a high Q factor via a superposition of magnetic forces. In the first method, we propose a large spatial superposition of a levitated spherical magnet generated via magnetic forces applied by adjacent flux qubits. We find that in this method the spatial superposition extent Δz is independent of the size of the particle. In the second method, we propose a large spatial superposition of a magnetically levitated flux qubit, generated via our driving the levitated qubit inductively. In both schemes, we show that ultralarge superpositions Δz/δzZPM∼104–106 are possible, where δzZPM is the zero-point motional extent.

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Phys. Rev. Applied 24, 024061– Published 26 August, 2025
  • Received 20 July 2023
  • Revised 19 June 2025
  • Accepted 20 June 2025
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