We are glad to announce the next Quantum Science and Technology Seminar

 

"Quantum measurement and control of mechanical motion at room temperature"

 

Speaker: Lorenzo Magrini  (University of Wien)

 

Time/Place : Tuesday 29th March 2022 at 14:30 in Aula Caianiello - Department of Physics - Federico II

 

Online participation available via MS Teams at this link - IMPORTANT: In case your access is denied, log out from your institutional account and, after clicking on this link, open MS Teams in your web browser.

 

Abstract

The Heisenberg uncertainty principle establishes the frontier to the quantum realm. The position of a particle, the spin of an atom, the energy of a photon can only be known with finite precision. Realizing measurements close to this limit requires high efficiency and good environmental isolation. These are challenging tasks, especially with macroscopic systems and at room temperature. In this talk I will describe how the motion of a glass sphere (150 nm diameter) levitated at room temperature can be measured and controlled close to this quantum limit. This is achieved by confocal microscopy, which, together with optimal control theory allows us to track the quantum trajectory of the particle in real time and to use feedback to reduce its energy to the quantum ground state.  Finally I will show how this efficient quantum measurement is also used to observe light squeezing by radiation pressure forces on the oscillating particle even without an optical resonator.  Achieving this level of quantum control by measurement and feedback on a levitated system that is made of billions of atoms and at room temperature represents an important step for the development of extraordinary force and impulse sensors and will perhaps help future experiments addressing some of the most intriguing open questions in fundamental physics.

 

The seminar is proposed by P. Lucignano, D. Montemurro, D. Massarotti, V. D'Ambrosio, F. Cardano and M. Esposito, as part of an initiative to present recent progress in the context of quantum sciences and technologies. A complete list of the past and upcoming seminars can be found here