Large Quantum Delocalization of a Levitated Nanoparticle Using Optimal Control: Applications for Force Sensing and Entangling via Weak Forces

Author(s)
T. Weiss, M. Roda-Llordes, E. Torrontegui, M. Aspelmeyer, O. Romero-Isart
Abstract

We propose to optimally control the harmonic potential of a levitated nanoparticle to quantum delocalize its center-of-mass motional state to a length scale orders of magnitude larger than the quantum zero-point motion. Using a bang-bang control of the harmonic potential, including the possibility of inverting it, the initial ground-state-cooled levitated nanoparticle coherently expands to large scales and then contracts to the initial state in a time-optimal way. We show that this fast loop protocol can be used to enhance force sensing as well as to dramatically boost the entangling rate of two weakly interacting nanoparticles. We parameterize the performance of the protocol, and therefore the macroscopic quantum regime that could be explored, as a function of displacement and frequency noise in the nanoparticle's center-of-mass motion. This noise analysis accounts for the sources of decoherence relevant to current experiments.

Organisation(s)
Quantum Optics, Quantum Nanophysics and Quantum Information
External organisation(s)
Österreichische Akademie der Wissenschaften (ÖAW), Leopold-Franzens-Universität Innsbruck, Universidad Carlos III de Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Vienna Center for Quantum Science and Technology (VCQ)
Journal
Physical Review Letters
Volume
127
No. of pages
6
ISSN
0031-9007
DOI
https://doi.org/10.1103/PhysRevLett.127.023601
Publication date
07-2021
Peer reviewed
Yes
Austrian Fields of Science 2012
103025 Quantum mechanics
Portal url
https://ucris.univie.ac.at/portal/en/publications/large-quantum-delocalization-of-a-levitated-nanoparticle-using-optimal-control-applications-for-force-sensing-and-entangling-via-weak-forces(23a9d52b-54e5-4ed3-9e72-0aca49c27225).html