The Quan2m group gathers condensed matter physicists exploring quantum states hosted by two-dimensional materials (graphene and transition metal dichalcogenides for instance). We focus on quantum states involving different kinds of excitations, electronic, phononic or magnonic, possibly related to strong interaction effects, and seek ways to tune these interactions. This is done via, e.g., electromagnetic fields, mechanical deformations, the proximity to magnetic or superconducting materials, or by controlling structural parameters such as the twist angle between two stacked 2D materials.
The group’s research currently deals with four classes of effects, respectively relevant in (i) quantum optoelectronics, (ii) quantum engineering, (iii) optothermics and (iv) 2D ordering phenomena. We operate various equipments to probe these effects: low-temperature magnetotransport setups, optical spectroscopy measurement lines, and a comprehensive platform (2Dfab) for the fabrication of artificial 2D heterostacks. Besides, we have direct access to various growth, advanced nanocharacterization, and nanofabrication facilities.
Quantum optoelectronics
Quantum engineering
Optothermics
2D ordering phenomena
The variety of available low-dimensional systems gives access to a wealth of electronic properties, among which direct bandgap allows for optoelectronic applications. Interestingly, all low-dimensional materials we investigate exhibit optical phonons that couple to electrons and can be probed with Raman spectroscopy.
We investigate interlayer and intralayer excitons, free carriers in low-dimensional materials in a transistor configuration, excitonic interactions, defects as photon sources [1,2]. Photoluminescence and Raman spectroscopy along with electronic transport provide insights into the electronic structure and transitions at play in heterostructures. In addition, we take advantage of the possible functionalization of low-dimensional systems via pi-stacked molecules to explore phenomena such as charge or energy transfer as well as light-activated tunneling [3].
[1] S. Dubey et al., ACS Nano 11, 11206 (2017)
[2] G. Nayak et al., Phys. Rev. Materials 11, 114001 (2019)
[3] Y. Chen et al., Advanced Materials 31, 1902917 (2019).
Contact : laetitia.marty@neel.cnrs.fr
We couple two dimensional materials to confined electromagnetic fields in order to study interacting quantum systems in different regimes.
In superconducting circuits, working with microwave photons, we integrate graphene electronic transport channels and exploit their unique gate tunability. More specifically, we have recently demonstrated a gate tunable Josephson parametric amplifier that operates at the quantum limit [1]. The tunability of graphene Josephson junctions is also promising for the gate tunable superconducting Qubits we are currently developing.
In the optical domain, we integrate 2D transition metal dichalcogenides (TMDC) within microcavities. We focus on the interaction between optical excitations (i.e. excitons), which is peculiar in TMDCs, in order to demonstrate non-classical sources of photons [2].
[1] G. Butseraen et al., Nat. Nanotechnol. 17, 1147 (2022)
[2] P. Stepanov et al., Phys. Rev. Lett. 126, 167401 (2021)
Contact: julien.renard@neel.cnrs.fr
A monolayer transition metal dichalcogenides inserted in an optical microcavity
A graphene based Josephson junction can be inserted in a microwave cavity to allow gate tunability
One-atom thick membranes, which are surfaces with no bulk exhibit unusual thermal and mechanical properties. In particular, graphene exhibits very high thermal conductivity and thermal regimes not fully elucidated yet.
We use optical techniques, in particular Raman spectroscopy, for thermal measurements of 2D membranes. We recently implemented a two-laser approach using one laser as the heater and the other as the local temperature probe. This allows imaging the spatial temperature distribution and thereby directly determining heat fluxes, which we analyse with models beyond the Fourier law [1]. This opens new perspectives on thermal transport at the nanoscale.
[1] P. Singh et al., PhD manuscript, UGA (2022)
In two-dimensional systems, a multitude of commensurate and incommensurate phases, topological phase transitions, highly degenerate ground states, etc, can occur. We explore such phases related to structural (e.g. moiré patterns), spin (e.g. magnetically-ordered phases) and charge (e.g. charge density waves, superconducting states) degrees of freedom, in presence of classical and quantum kinds of interactions.
We investigate these (dis)order phenomena in epitaxial two-dimensional systems (graphene, transition metal dichalcogenides) forming various kinds of commensurate and incommensurate super-orders ; and in exfoliated metallic transition metal dichalcogenides, some of which are prone to electronic instabilities mediated by interactions with phonons (TaS2, TaSe2) and others to magnetic ordering up to room temperature (CrTe2). Thickness-dependent order/disorder is probed at the atomic scale with scanning tunneling microscopy, with high-resolution synchrotron X-ray diffraction, and with the help of optical probes, Raman spectroscopy and magneto-optical Kerr effect magnetometry at variable temperatures and with spatial resolution.
[1] A. Purbawati, S. Sarkar et al. ACS Appl. Elec. Mater. ASAP article
[2] S. Layek et al.,. Carbon, 201, 667 (2023).
[3] S. Lisi et al. Phys. Rev. Lett. 129, 096101 (2022)
[4] A. Purbawati et al. ACS Appl. Mater. Interf. 12, 30702 (2020)
Contact: johann.coraux@neel.cnrs.fr
Van der Waals heterostructures, tailor-made crystals obtained by stacking 2D materials, open a wide range of new functions in condensed matter. Fine tuning of the different interactions at play in 2D heterostructures is achieved with the use of few layer graphene electrostatic gates, with the controlled mismatch angle between layers and other nanofabrication techniques compatible with 2D materials.
The 2Dfab platform is operated in collaboration with the QNES team, and with support from the Nanofab and Experimental Engineering technical groups of the lab. It gathers state-of-the-art, in-house-developed manipulation tools including micro-transfer stages for dry stamping 2D materials one of which is operated within our Ar glove-box. Further processing can be performed like annealing, or surface treatments in a clean chemistry room, while device fabrication is performed at the Nanofab facility.
[1] D. Dufeu, et al., Highlights – Institut Néel, 20 (2016).
[2] L. Marty, et al., Nanosciences Fondation Graphene Highlights, 25 (2013).
Position type: Stages Master-2 & Thèse
Contact: Bendiab Nedjma - 0476887906 | Marty Laetitia - 0456387042
At the nanometric scale, the geometry and dimensions of devices have a major impact on thermal properties of 2D matérials due to the interaction between energy carriers and the dimensions characteristic of nanomaterials, whereas these effects are negligible in massive materials.
This experimental and theoretical field linked to nano-phononics and energy at small scales is in full development, and aims to review the concepts and macroscopic laws of the dissipation of various energy carriers. The thermoelectric power of nanostructures in general remains a vast field of study underway to gain a better fundamental understanding, but also with a view to applications in thermal rectification, heat management in devices and also with a view to recovering ambient thermal energy and converting it into electrical energy.
The aim of this internship is to measure and understand the heat transport on graphene depending on its geometry, defects, strain and doping.
Position type: Stages Master-2 & Thèse
Contact: Coraux Johann - 0476881289 | Rougemaille Nicolas - 0476887427
Frustrated systems host intriguing states of matter, for instance having non-zero entropy at zero temperature. Our group explores their physics at different lengthscales and with different kinds of degree of freedom (magnetic, structural), in two-dimensional (2D) lattices. Going beyond our usual static 2D imaging of correlated disorder in these systems, the internship addresses the time dimension, to understand how disorder dynamically evolves, possibly in a spatially and temporally correlated way between different regions of the lattices.
Position type: Stages Master-2 & Thèse
Contact: RENARD Julien -
The goal of the project is to develop a technique to probe new electronic excitations in artificial van der Waals quantum materials.
Position type: Stages Licence & Master-1
Contact: RENARD Julien -
The goal of this project is to develop electrically tunable superconducting quantum circuits that could be used in the next generation of quantum devices.
Position type: Stages Master-2 & Thèse
Contact: RENARD Julien -
The goal of this project is to develop electrically tunable superconducting quantum circuits that could be used in the next generation of quantum devices.
Position type: Poste permanent
Contact: Virginie SIMONET -
Appel à candidatures : CDD 4 ans, à visée poste permanent
Repousser les frontières dans les Matériaux Quantiques
La Loi de Programmation pour la Recherche a créé un nouveau type de contrat de pré-titularisation.
Les chaires de professeur junior constituent une nouvelle voie de recrutement sur projet de recherche et d’enseignement permettant à son terme, entre 3 et 6 ans, et après évaluation de la valeur scientifique et de l’aptitude professionnelle de l’agent par une commission d’évaluation, d’accéder à un emploi titulaire dans le corps des directeurs de recherche.
Descriptif du projet :
Les matériaux quantiques sont le point de rencontre de plusieurs communautés fortes de l’Institut de Physique et leur exploration a vocation à préparer le futur des technologies quantiques. L’un des enjeux est de mieux comprendre, contrôler et exploiter les interactions électroniques et fluctuations quantiques pour concevoir des matériaux avec de nouvelles fonctionnalités. Cette CPJ a vocation à soutenir ce domaine de recherche, et en particulier à explorer les excitations et/ou les propriétés hors-équilibre des matériaux quantiques en s’appuyant notamment sur des expériences innovantes, ou réalisées en conditions extrêmes, ou exploitant des stimuli extérieurs pour sonder la dynamique des états excités de ces matériaux à des temps ultra-courts. Les candidates et les candidats devront proposer un projet de recherche sur les matériaux quantiques s’intégrant au sein de l’un de ces quatre laboratoires d’accueil : l’Institut Néel à Grenoble, l’Institut de Physique et de Chimie des Matériaux de Strasbourg, le Laboratoire National des Champs Magnétiques Intenses à Grenoble et Toulouse, le Laboratoire de Physique des Solides à Orsay. Les projets de recherche associant l’un de ces laboratoires avec l’axe “Matériaux Quantiques” du Laboratoire de Recherche International « Frontières Quantiques » à Sherbrooke au Canada sont encouragés.
Un projet d’enseignement en lien avec la thématique « matériaux quantiques » sera discuté avec la tutelle universitaire du laboratoire d’accueil de la CPJ.
Mots-clés :
Matériaux quantiques, spectroscopies, interaction lumière-matière, conditions extrêmes, propriétés électroniques et optoélectroniques
Etapes |
Dates |
Ouverture des inscriptions |
20 février 2023 |
Clôture candidature |
14 avril 2023 |
Auditions |
mai-juin 2023 |
Pour plus d’information cliquez ici
Person in charge: Laetitia MARTY
Invited & Others
Amritesh SHARMA
Personnel Chercheur - Pittsburgh University
Referent: Julien RENARD