Postdoctoral position (M/F): Quantum states of motion of optomechanical resonators

Job Description

Missions

The motion of massive, mesoscopic-scale mechanical resonators can behave quantum mechanically when cooled down to ultra-low temperatures. The exploration of such systems in the quantum regime has both fundamental and practical interests: as a test of quantum mechanics in systems beyond the few-particle ensembles, and its interplay with gravitation; or as a light-matter interface for the development of quantum communication networks, for storing and transducing quantum information.

A mechanical resonator, such as the micrometer-sized disks fabricated in our team, also confines optical modes that strongly interact with the motion. Therefore, light provides a means to shape the quantum state of motion of such an object when prepared close to its ground state (the 'phonon vacuum'), by adding or removing phonons one by one. This project aims to do so and targets the generation of Fock and superposition states chosen arbitrarily in the low phonon number regime. Light also probes the obtained states, which will then be characterized through optical tomographic reconstruction.

Using the same methodology, this project also seeks to achieve multipartite quantum control in systems composed of several of these optomechanical resonators, either evanescently coupled or arranged in an interferometric configuration. It will target in particular the generation of maximally-entangled GHZ states, of importance in quantum computing protocols, or N00N states, of interest for sensing with sub-standard quantum limit sensitivity and offering the possibility to explore the concept of nonlocal influence in quantum mechanics.

References:
I. Favero and K. Karrai, Nat. Phot. 3, 201 (2009); M. Aspelmeyer, T. Kippenberg and F. Marquardt, Rev. Mod. Phys. 86, 1391 (2014)
S. Barzanjeh, Nat. Phys. 10, 1038 (2021)
M.R. Vanner, M. Aspelmeyer and M.S. Kim, PRL 110, 010504 (2013); M.R. Vanner, I. Pikovski, and M.S. Kim, Ann. Phys. 527 (2015)
A. Barbero, S. Pautrel, …, A. Borne, I. Favero (2026)

Activity

The research focuses on fundamental studies in quantum optomechanics, conducted using semiconductor disk nanoresonators. It will combine optical experiments, instrumentation, cryogenic environments, cleanroom microfabrication, theoretical models, numerical simulations.

Your Profil

Skills

We are seeking a highly motivated candidate with a Ph.D. in quantum optics or quantum physics and solid experimental experience. A subset of the following skills is desirable: setting up optical experiments, instrumentation, cleanroom nanofabrication, proficiency in theoretical frameworks, and numerical modeling.
Additionally: fluency in spoken and written English, independence, ability to work in a team

Your Work Environment

Materials and Quantum Phenomena laboratory (MPQ) is a joint research unit between the French National Center for Scientific Research (CNRS) and Université Paris Cité. The laboratory specializes in the study of frontier quantum materials and the development of novel quantum devices.

The LIght and MEchanics (LIME, https://mpq.u-paris.fr/en/lime-en/) team studies the interactions between light and miniature mechanical resonators (micro- or nanomechanical). The team addresses both fundamental questions (quantum behavior of mechanical systems, decoherence phenomena at mesoscopic scales), and applications, notably in the field of optical and mechanical sensors. Thanks to its strong nanotechnology background, LIME ventures into multidisciplinary fields involving semiconductors, fluidics, biophysics and the development of new types of microscopes.

The postdoctoral fellow will join the quantum optomechanics activity in semiconductor microdisks and will benefit from an operational experimental environment for the project (optics, cryogenics, instrumentation), computing tools and access to the clean room of the laboratory.

Constraints and risks

The work will primarily focus on optical experiments (at low magnification) conducted at ultra-low temperatures (in a cryogenic environment). Some work in a cleanroom is also planned. This 150-square-meter facility is equipped with all the necessary equipment for fabricating micro- and nano-devices: optical and electronic lithography, wet and dry etching, thin-film deposition, and characterization.

Compensation and benefits

Compensation

From 3131€ grossly per month depending on experience

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions