Testing dissipative collapse models with a levitated micromagnet

Vinante, A., Gasbarri, G., Timberlake, C., Toros, M. and Ulbricht, H. (2020) Testing dissipative collapse models with a levitated micromagnet. Physical Review Research, 2, 043229. (doi: 10.1103/PhysRevResearch.2.043229)

Abstract

We present experimental tests of dissipative extensions of spontaneous wave function collapse models based on a levitated micromagnet with ultralow dissipation. The spherical micromagnet, with a radius R = 27 μ m , is levitated by the Meissner effect in a lead trap at 4.2 K and its motion is detected by a superconducting quantum interference device. We perform accurate ringdown measurements on the vertical translational mode with frequency 57 Hz and infer the residual damping at vanishing pressure γ / 2 π < 9 μ Hz . From this upper limit we derive improved bounds on the dissipative versions of the continuous spontaneous localization (CSL) and the Diósi-Penrose (DP) models with proper choices of the reference mass. In particular, dissipative models give rise to an intrinsic damping of an isolated system with the effect parametrized by a temperature constant; the dissipative CSL model with temperatures below 1 nK is ruled out, while the dissipative DP model is excluded for temperatures below 10 − 13 K . Furthermore, we present the bounds on dissipative effects in a more recent model, which relates the wave function collapse to fluctuations of a generalized complex-valued space-time metric.

• Item Type: Articles
• Additional Information: A.V., C.T., G.G., and H.U. acknowledge financial support from the EU H2020 FET project TEQ (Grant No. 766900), the Leverhulme Trust (Grant No. RPG-2016-046), the COST Action QTSpace (Grant No. CA15220), and the Foundational Questions Institute. M.T. acknowledges financial support from EPSRC (Grant No. EP/N031105/1).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Toros, Dr Marko
• Authors: Vinante, A., Gasbarri, G., Timberlake, C., Toros, M., and Ulbricht, H.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review Research
• Publisher: American Physical Society
• ISSN: 2643-1564
• ISSN (Online): 2643-1564
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Physical Review Research 2:043229
• Publisher Policy: Reproduced under a Creative Commons licence