A5086621086- 2D Materials and Applications
- Perovskite Materials and Applications
- Physics of Superconductivity and Magnetism
- Graphene research and applications
- Quantum and electron transport phenomena
- MXene and MAX Phase Materials
- Iron-based superconductors research
- Quantum Dots Synthesis And Properties
- Magnetic and transport properties of perovskites and related materials
- Mechanical and Optical Resonators
- Magnetism in coordination complexes
- Spectroscopy and Quantum Chemical Studies
- Chalcogenide Semiconductor Thin Films
- Magnetic properties of thin films
- Photoreceptor and optogenetics research
- Inorganic Chemistry and Materials
- Magneto-Optical Properties and Applications
- Quantum optics and atomic interactions
- Strong Light-Matter Interactions
- Organic and Molecular Conductors Research
- Advanced Semiconductor Detectors and Materials
- Lanthanide and Transition Metal Complexes
- Advanced NMR Techniques and Applications
- Multiferroics and related materials
- Semiconductor Quantum Structures and Devices
Laboratoire National des Champs Magnétiques Intenses
2018-2024
Centre National de la Recherche Scientifique
2018-2024
Université Grenoble Alpes
2018-2024
Paul Scherrer Institute
2023-2024
Institut National des Sciences Appliquées de Toulouse
2020-2024
Université Toulouse III - Paul Sabatier
2020
Université Joseph Fourier
2018
Palacký University Olomouc
2018
We present a comprehensive optical study of the excitonic Zeeman effects in transition metal dichalcogenide monolayers, which are discussed comparatively for selected materials: MoSe2, WSe2 and WS2. introduce simple semi-phenomenological description magnetic field evolution individual electronic states fundamental sub-bands by considering three additive components: valley, spin orbital terms. corroborate validity proposed inspecting Zeeman-like splitting neutral charged resonances...
The hybridization of magnons (spin waves) with phonons, if sufficiently strong and comprising long wavelength excitations, may offer a new playground when manipulating the magnetically ordered systems light. Applying magnetic field to quasi-two-dimensional antiferromagnet, $\mathrm{Fe}{\mathrm{PS}}_{3}$, we tune magnon-gap excitation coincide initially lower-in-energy phonon modes. Hybrid magnon-phonon modes, magnon polarons are unveiled demonstration pronounced avoided crossing between...
Embedding a WS2 monolayer in flakes of hexagonal boron nitride allowed us to resolve and study the photoluminescence response due both singlet triplet states negatively charged excitons (trions) this atomically thin semiconductor. The energy separation between has been found be relatively small reflecting rather weak effects electron–electron exchange interaction for trion monolayer, which involves two electrons with same spin but from different valleys. Polarization-resolved experiments...
Significance Well‐defined defect centers play a crucial role in condensed-matter physics. That is particularly evident the case of semiconductors and wide‐gap insulators, where midgap levels provide number versatile functionalities: from lasing to pressure sensing. Individual defects may become single-photon sources—crucial for applications quantum technology. Recently, such have been observed hexagonal boron nitride (hBN). Here, method fabricate stable reproducible hBN introduced. Large...
Optical magneto-spectroscopy methods (Raman scattering, far-infrared transmission, and photoluminescence) have been applied to investigate the properties of ${\mathrm{NiPS}}_{3}$ semiconducting antiferromagnet. The fundamental magnon gap excitation in this van der Waals material has found be split into two components, support biaxial character Photoluminescence measurements near-infrared spectral range show that intriguing 1.475 eV unique antiferromagnetic phase splits upon application...
We report experimental and theoretical studies on the magnetoelastic interactions in MnPS3. Raman scattering response measured as a function of temperature shows blue shift active modes at 120.2 155.1 cm−1, when is raised across antiferromagnetic-paramagnetic transition. Density functional theory (DFT) calculations have been performed to estimate effective exchange calculate phonon modes. The lead conclusion that peculiar behavior with two low energy can be explained by symmetry their...
Abstract Strong Coulomb correlations together with multi-valley electronic bands in the presence of spin-orbit interaction are at heart studies rich physics excitons monolayers transition metal dichalcogenides (TMD). Those archetypes two-dimensional systems promise a design new optoelectronic devices. In intrinsic TMD basic, intravalley excitons, formed by hole from top valence band and an electron either lower or upper spin-orbit-split conduction subbands: one these is optically active,...
Magnetic layered materials have emerged recently as promising systems to introduce magnetism in structures based on two-dimensional (2D) and investigate exotic magnetic ground states the 2D limit. In this work, we apply high hydrostatic pressures up P ≈ 8.7 GPa bulk antiferromagnet FePS3 tune collective lattice excitations (phonons) resonance with (magnons). Close = 4 GPa, magnon-phonon is achieved, strong coupling between these modes leads formation of new quasiparticles, magnon-polarons,...
Understanding the optical properties of interlayer excitons in bulk transition metal dichalcogenides.
Identifying quantum numbers to label elementary excitations is essential for the correct description of light-matter interaction in solids. In monolayer semiconducting transition metal dichalcogenides (TMDs) such as MoSe$_2$ or WSe$_2$, most optoelectronic phenomena are described well by labelling electron and hole states with spin projection along normal layer (S$_z$). contrast, WSe$_2$/MoSe$_2$ interfaces recent experiments show that taking S$_z$ number not a good approximation, mixing...
We perform coherent nonlinear spectroscopy of excitons in single-layers MoSe$_2$ and WSe$_2$ encapsulated between thin films hexagonal boron nitride. Employing four-wave mixing microscopy we identify virtually disorder free areas, generating exciton optical response at the homogeneous limit. Focussing on such measure broadening as a function environmental factors, namely temperature density. Exploiting FWM imaging, find that locations, absorption excited states their couplings can be...
The spectral signatures associated with different negatively charged exciton complexes (trions) in a WS2 monolayer encapsulated hBN are analyzed from low temperature and polarization resolved reflectance contrast (RC) photoluminescence (PL) experiments, an applied magnetic field. Based on results obtained the RC experiment, we show that valley Zeeman effect affects optical response of both singlet triplet trion species through evolution their energy relative intensity, when applying external...
The molecular self‐assembly and the magnetic properties of two cyclooctatetraenide (COT)‐based single‐ion magnets (SIM) adsorbed on Ag(100) in sub‐monolayer (ML) range are reported. Our study combines scanning‐tunneling microscopy, X‐ray photoemission spectroscopy polarized absorption to show that Cp*ErCOT (Cp* = 1,2,3,4,5‐pentamethylcyclopentadienide anion) SIMs self‐assemble as alternating compact parallel rows including standing‐up lying‐down conformations, following main crystallographic...
Abstract Magneto-spectroscopy methods have been employed to study the zero-wavevector magnon excitations in MnPSe 3 . Experiments carried out as a function of temperature and applied magnetic field show that two low-energy branches its antiferromagnetic phase are gapped. The observation gaps (at 1.70 ± 0.05 meV 0.09 0.01 meV) implies is biaxial antiferromagnet. A relatively strong out-of-plane anisotropy imposes spin alignment be in-plane whereas directionality within plane governed by...
We report on magneto-optical studies of the quasi-two-dimensional van der Waals antiferromagnet FePS3. Our measurements reveal an excitation that closely resembles antiferromagnetic resonance mode typical easy-axis antiferromagnets; nevertheless, it displays unusual, four-times larger Zeeman splitting in applied magnetic field. identify this with |Sz| = 4 multipolar magnon─a single-ion 4-magnon bound state─that corresponds to a full reversal single moment Fe2+ ion. argue condensation magnons...
Abstract The possibility of almost linear tuning the band gap and electrical optical properties in monolayers (MLs) semiconducting transition metal dichalcogenide (S-TMD) alloys opens up way to fabricate materials with on-demand characteristics. By making use photoluminescence spectroscopy, we investigate WSSe MLs a S/Se ratio 57/43 deposited on SiO 2 /Si substrate encapsulated hexagonal BN flakes. Similarly ‘ parent ’ WS WSe MLs, assign ML family dark ground exciton state. We find that,...
We present a comprehensive optical study of the excitonic Zeeman effects in transition metal dichalcogenide monolayers, which are discussed comparatively for selected materials: MoSe$_2$, WSe$_2$ and WS$_2$. introduce simple semi-phenomenological description magnetic field evolution individual electronic states fundamental sub-bands by considering three additive components: valley, spin orbital terms. corroborate validity proposed inspecting Zeeman-like splitting neutral charged resonances...
Abstract Monolayers of transition metal dichalcogenides display a strong excitonic optical response. Additionally encapsulating the monolayer with hexagonal boron nitride allows to reach limit purely homogeneously broadened exciton system. On such MoSe 2 ‐based system, ultrafast six‐wave mixing spectroscopy is performed and novel destructive photon echo effect found. This process manifests as characteristic depression nonlinear signal dynamics when scanning delay between applied laser...
We present an experimental setup developed to perform optical spectroscopy experiments (Raman scattering and photoluminescence measurements) with a micrometer spatial resolution in extreme environment of low temperature, high magnetic field, pressure. This unique setup, the best our knowledge, allows us deeply explore phase diagram condensed matter systems by independently tuning these three thermodynamic parameters while monitoring low-energy excitations (electronic, phononic, or...
The molecular self-assembly and the magnetic properties of two cyclooctatetraenide (COT) - based single-ion magnets (SIM) adsorbed on Ag(100) in sub-monolayer range are reported. Our study combines scanning-tunneling microscopy, X-ray photoemission spectroscopy polarized absorption to show that Cp*ErCOT (Cp* = 1,2,3,4,5-pentamethylcyclopentadienide anion) SIMs self-assemble as alternating compact parallel rows including standing-up lying-down conformations, following main crystallographic...
Optical magneto-spectroscopy methods (Raman scattering, far-infrared transmission, and photoluminescence) have been applied to investigate the properties of NiPS3 semiconducting antiferromagnet. The fundamental magnon gap excitation in this van der Waals material has found be split into two components, support biaxial character Photoluminescence measurements near-infrared spectral range show that intriguing 1.475 eV-excitation unique antiferromagnetic phase splits upon application in-plane...
Magneto-spectroscopy methods have been employed to study the zero-wavevector magnon excitations in MnPSe$_3$. Experiments carried out as a function of temperature and applied magnetic field show that two low-energy branches MnPSe$_3$ its antiferromagnetic phase are gapped. The observation gaps (at 14 0.7 cm$^{-1}$) implies is biaxial antiferromagnet. A relatively strong out-of-plane anisotropy imposes spin alignment be in-plane whereas directionality within plane governed by factor 2.5...
Metamaterials, fabricated by assembling different compounds at the nanoscale, can have properties not found in naturally occurring materials, and therefore offer new avenues to develop novel devices. In realm of spintronics, where spin electrons is used extend capabilities electronic devices, quest for such functional materials has expanded towards magnetic oxides. Here, finding methods control their anisotropy crucial achieve higher memory density longer stability. order address this...