Postdoctoral researcher (M/F) in strong coupling in chiral photonic metamaterials near an optical Weyl point

Job Description

Missions

Weyl points are discrete points in the first Brillouin zone of a three-dimensional crystal where two bands intersect linearly. In the vicinity of a Weyl point, the quasiparticles are referred to as Weyl fermions, which are the solid-state analogs of massless relativistic particles. Crystals whose band structure contains Weyl points typically exhibit chiral edge states localized at the crystal surface and topologically protected against coupling to bulk states. These materials, known as Weyl semimetals, can therefore display high electronic mobilities, making them highly attractive for electronic applications [1]. Photonic analogs of Weyl semimetals have also been identified, notably in chiral photonic crystals [2] and metamaterials [3]. These systems are characterized by a periodic modulation of the refractive index that satisfies specific symmetry requirements. Several remarkable phenomena associated with photonic Weyl points have been demonstrated, including robust surface states and novel electromagnetic scattering laws [4]. Over the past decades, the possibility of controlling material properties, such as electronic transport [5], by coupling selected electronic transitions to the photonic modes of a resonant cavity has attracted considerable attention and given rise to a new research field called « polaritonics » [6]. Topological polaritonics, which consists of coupling a topological electronic system to photonic modes, is currently experiencing rapid development [7-9]. It is important to emphasize, however, that the possibility of coupling topological states of matter to chiral photonic edge modes that are themselves topologically nontrivial and spatially localized remains largely unexplored.

The successful candidate (M/F) will carry out theoretical investigations combining analytical models based on a Hamiltonian formalism with electromagnetic simulations using finite-element and finite-difference time-domain (FDTD) methods. These tools will be used to explore the potential of various experimentally relevant platforms for achieving strong or ultrastrong light-matter interactions between a topological electronic system, such as quantum Hall systems, SSH-type models, or two-dimensional materials, and chiral photonic edge modes in the vicinity of an optical Weyl point.

[1] C. Shekhar et al., Nat. Phys. 11, 645 (2015)
[2] W.J. Chen, M. Xiao, and C.T. Chan, Nat. Commun. 7, 13038 (2016)
[3] B. Yang et al., Nat. Commun. 8, 97 (2017)
[4] M. Zhou et al., Nat. Commun. 8, 1388 (2017)
[5] E. Orgiu et al., Nat. Mater. 14, 1123 (2015)
[6] J. Bloch et al., Nature 606, 41 (2022)
[7] C.A. Downing et al., Phys. Rev. Lett. 123, 217401 (2019)
[8] F. Appugliese et al., Science 375, 1030 (2022)
[9] T.F. Allard and G. Weick, Phys. Rev. B 108, 245417 (2023)
[10] N.S. Mueller et al., Nature 583, 780 (2020)
[11] F. Tay et al., Nat. Commun. 16, 3603 (2025)
[12] S. Lamowski et al., Phys. Rev. B 97, 125409 (2018)

Activity

-Electromagnetic simulations of various chiral structures exhibiting optical Weyl points
-Analysis of the spatial profiles of the photonic modes and their degree of polarization
-Identification of a suitable geometry enabling the coupling of photonic modes to material excitations, to be determined in collaboration with experimentalists
-Development of a Hamiltonian model describing the light-matter coupling
-Investigation of the eigenmodes of the Hamiltonian and calculation of the transmission spectrum
-Study of the topological properties of the coupled system

Your Profil

Skills

-Strong background in light-matter interactions, particularly in the non-perturbative coupling regimes, as well as in condensed-matter physics
-Good written and spoken English communication skills. Minimum B2 level (CEFR)
-Ability to present, communicate, and disseminate scientific results
-Ability to work independently as well as collaboratively within a research team

Your Work Environment

The successful candidate (M/F) will join the Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), a joint research unit of the CNRS and the University of Strasbourg, located on the Cronenbourg campus in Strasbourg, France.

The laboratory brings together more than 220 staff members, including researchers, faculty members, engineers, doctoral candidates, and technical personnel. Research activities at IPCMS cover a broad range of topics in materials physics and chemistry, spanning nanoscience and quantum materials, photonics, magnetism, surfaces and interfaces, as well as molecular and functional materials.

The successful candidate (M/F) will join a highly dynamic research environment within the Mesoscopic Physics group, which currently comprises five permanent researchers, four PhD students, and two postdoctoral researchers. The project will be jointly supervised by Guillaume Weick, Associate Professor at the University of Strasbourg and specialist in the topological properties of materials, and David Hagenmuller, CNRS researcher specializing in light-matter interactions in the non-perturbative coupling regimes. The project is part of the national project TORNADO funded by the PEPR LUMA involving 13 different laboratories with outstanding expertise in chiral light-matter interactions. The successful candidate (M/F) will benefit from on-campus university dining facilities, convenient access to public transportation, and the various benefits and services offered by the CNRS to its staff.

Constraints and risks

The project and position do not involve any specific constraints or particular risks. The work is performed during standard office hours, with no weekend work and no on-call duties

Compensation and benefits

Compensation

Starting from €3,071.50 gross 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