Reference : UMR5798-YANLOU-001
Workplace : TALENCE
Date of publication : Thursday, March 24, 2022
Scientific Responsible name : Yann Louyer
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 September 2022
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
Macroscopic quantum optomechanics is of great interest for testing fundamental physics, such as quantum-classical transitions. In this context, levitating optomechanics is promising, as it is extremely well isolated from the environment by demonstrating the largest mechanical Q-factor and ground state cooling for a single degree of freedom of motion, while operating at room temperature. The goal of this thesis is to achieve the fundamental quantum state of center-of-mass motion of an optically tweezed nanoparticle using feedback cooling. By construction, this system will have the ability to detect forces (< zN) applied to the particle in real time. The modified optical properties of core-shell silicon particles (<300 nm in size) will enable cooling efficiencies approximately ten times greater than those of silica particles. This will open up new possibilities, for example, for the preparation of non-classical macroscopic states, for testing the foundations of quantum mechanics , with applications in ultraweak force detection  and precision gravimetry .
 O. Romero-Isart et al, Large quantum superpositions and interference of massive nanometer-sized objects, Phys. Rev. Lett. 107 (2011) 020405.
 A.A. Geraci et al, Short-range force detection using optically cooled levitated microspheres, Phys. Rev. Lett. 105 (2010) 101101.
 S. Qvafort et al, Gravimetry through non-linear optomechanics, Nature Commun. 9 (2018) 3690.
The thesis will be carried out in the photonics and materials team of the LOMA (University of Bordeaux) comprising 18 researchers and professors. The research theme is the optical trapping of nanoparticles in vacuum.
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