Real-time optimal quantum control of mechanical motion at room temperature

Autor(en)

Lorenzo Magrini, Philipp Rosenzweig, Constanze Bach, Andreas Deutschmann-Olek, Sebastian G. Hofer, Sungkun Hong, Nikolai Kiesel, Andreas Kugi, Markus Aspelmeyer

Abstrakt

The ability to accurately control the dynamics of physical systems by measurement and feedback is a pillar of modern engineering(1). Today, the increasing demand for applied quantum technologies requires adaptation of this level of control to individual quantum systems(2,3). Achieving this in an optimal way is a challenging task that relies on both quantum-limited measurements and specifically tailored algorithms for state estimation and feedback(4). Successful implementations thus far include experiments on the level of optical and atomic systems(5-7). Here we demonstrate real-time optimal control of the quantum trajectory(8) of an optically trapped nanoparticle. We combine confocal position sensing close to the Heisenberg limit with optimal state estimation via Kalman filtering to track the particle motion in phase space in real time with a position uncertainty of 1.3 times the zero-point fluctuation. Optimal feedback allows us to stabilize the quantum harmonic oscillator to a mean occupation of 0.56 +/- 0.02 quanta, realizing quantum ground-state cooling from room temperature. Our work establishes quantum Kalman filtering as a method to achieve quantum control of mechanical motion, with potential implications for sensing on all scales. In combination with levitation, this paves the way to full-scale control over the wavepacket dynamics of solid-state macroscopic quantum objects in linear and nonlinear systems.Optimal quantum control of an optically trapped nanoparticle in its ground state is demonstrated at room temperature, using Kalman filtering to track its quantum trajectory in real time.

Organisation(en)

Quantenoptik, Quantennanophysik und Quanteninformation

Externe Organisation(en)

Technische Universität Wien, Universität Stuttgart, Austrian Institute of Technology, Österreichische Akademie der Wissenschaften (ÖAW), Vienna Center for Quantum Science and Technology (VCQ)

Journal

Nature

Band

595

Seiten

373-377

Anzahl der Seiten

5

ISSN

0028-0836

DOI

https://doi.org/10.1038/s41586-021-03602-3

Publikationsdatum

07-2021

Peer-reviewed

Ja

ÖFOS 2012

103025 Quantenmechanik, 103021 Optik

Schlagwörter

ASJC Scopus Sachgebiete

General

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/6495a52a-378c-4eb6-b548-5a375a984bd8