Publications (69)
Sub 10 nm Nanochannels Enable Directional Quasi Ballistic Exciton Transport over 5 μm at Room Temperature
Xiao-Jie Wang, Jia-Wei Tan, Xiao-Ze Li +9
Nanoscale potential wells provide a powerful means to engineer energy landscapes in low dimensional materials, enabling control over quantum states, carrier dynamics, and optoelect…
Entangled Telecom Photon Generation using Twisted Van der Waals Crystals
Nidhin Prasannan, Konstantinos Mourzidis, Vishwas Jindal +11
Nanoscale quantum light sources are essential building blocks for integrated quantum photonic systems. Here, we report a wavelength-scale entangled-photon source based on van der W…
Electrical Detection of Light Helicity using a Quantum Dots based Hybrid Device at Zero Magnetic Field
Fabian Cadiz, Delphine Lagarde, Bingshan Tao +13
Photon helicity-dependent photocurrent is measured at zero magnetic field on a device based on an ensemble of InGaAs/GaAs quantum dots that are embedded into a GaAs-based p-i-n dio…
Large-scale characterization of Cu2O monocrystals via Rydberg excitons
Kerwan Morin, Delphine Lagarde, Angélique Gillet +2
Rydberg states of excitons can reach microns in size and require extremely pure crystals. We introduce an experimental method for the rapid and spatially-resolved characterization…
Controlling the polarization eigenstate of a quantum dot exciton with light
Thomas Belhadj, Claire-Marie Simon, Thierry Amand +6
We demonstrate optical control of the polarization eigenstates of a neutral quantum dot exciton without any external fields. By varying the excitation power of a circularly polariz…
Optomechanical measurement of thermal transport in two-dimensional MoSe2 lattices
Nicolas Morell, Slaven Tepsic, Antoine Reserbat-Plantey +7
Nanomechanical resonators have emerged as sensors with exceptional sensitivities. These sensing capabilities open new possibilities in the studies of the thermodynamic properties i…
Intervalley electron-hole exchange interaction and impurity-assisted recombination of indirect excitons in WS and WSe monolayers
Pengke Li, Cedric Robert, Dinh Van Tuan +3
The variety of excitonic states in tungsten-based dichalcogenide monolayers stems from unique interplay between the spin and valley degrees of freedom. One of the exciton species i…
Dynamic nuclear polarization of a single charge-tunable InAs/GaAs quantum dot
Benoît Eble, Olivier Krebs, Aristide Lemaître +6
We report on the dynamic nuclear polarization of a single charge-tunable self-assembled InAs/GaAs quantum dot in a longitudinal magnetic field of 0.2T. The hyperfine interact…
Imaging Seebeck drift of excitons and trions in MoSe2 monolayers
Sangjun Park, Bo Han, Caroline Boule +10
Hyperspectral imaging at cryogenic temperatures is used to investigate exciton and trion propagation in MoSe monolayers encapsulated with hexagonal boron nitride (hBN). Under a…
Unveiling the optical emission channels of monolayer semiconductors coupled to silicon nanoantennas
Jean-Marie Poumirol, Ioannis Paradisanos, Shivangi Shree +13
Monolayers (MLs) of transition metal dichalcogenides (TMDs) such as WSe2 and MoSe2 can be placed by dry stamping directly on broadband dielectric resonators, which have the ability…
Large perpendicular magnetic anisotropy in Ta/CoFeB/MgO on full coverage monolayer MoS2 and first principle study of its electronic structure
Ziqi Zhou, Paul Marcon, Xavier Devaux +18
Perpendicularly magnetized spin injector with high Curie temperature is a prerequisite for developing spin optoelectronic devices on 2D materials working at room temperature (RT) w…
Stability of the In-Plane Room Temperature van der Waals Ferromagnet Chromium Ditelluride and Its Conversion to Chromium-Interleaved CrTe Compounds
Anike Purbawati, Suman Sarkar, Sébastien Pairis +19
Van der Waals magnetic materials are building blocks for novel kinds of spintronic devices and playgrounds for exploring collective magnetic phenomena down to the two-dimensional l…
Exciton self-trapping in twisted hexagonal boron nitride homostructures
Sébastien Roux, Christophe Arnold, Etienne Carré +17
One of the main interests of 2D materials is their ability to be assembled with many degrees of freedom for tuning and manipulating excitonic properties. There is a need to underst…
Interlayer excitons in bilayer MoS2 with strong oscillator strength up to room temperature
Iann C. Gerber, Emmanuel Courtade, Shivangi Shree +8
Coulomb bound electron-hole pairs, excitons, govern the optical properties of semi-conducting transition metal dichalcogenides like MoS and WSe. We study optical transition…
Emission Dynamics of Rydberg Excitons in : Distinguishing Second Harmonic Generation from Secondary Emission
Kerwan Morin, Poulab Chakrabarti, Delphine Lagarde +5
Rydberg excitons in simultaneously give rise to two very different optical responses under resonant two-photon excitation: a coherent second-harmonic signal mediat…
Ultra-low power threshold for laser induced changes in optical properties of 2D Molybdenum dichalcogenides
Fabian Cadiz, Cedric Robert, Gang Wang +13
The optical response of traditional semiconductors depends on the laser excitation power used in experiments. For two-dimensional (2D) semiconductors, laser excitation effects are…
Magneto-optical determination of the carrier lifetime in coherent Ge(1-x)Sn(x)/Ge heterostructures
Elisa Vitiello, Simone Rossi, Christopher A. Broderick +6
We present a magneto-optical study of the carrier dynamics in compressively strained Ge(1-x)Sn(x) films having Sn compositions up to 10% epitaxially grown on blanket Ge on Si (001)…
Electronic structure of the Co(0001)/MoS2 interface, and its possible use for electrical spin injection in a single MoS2 layer
Thomas Garandel, Rémi Arras, Xavier Marie +2
The ability to perform efficient electrical spin injection from ferromagnetic metals into two-dimensional semiconductor crystals based on transition metal dichalcogenide monolayers…
Silicon nanoantennas for tailoring the optical properties of MoS2 monolayers
Danae Katrisioti, Peter R. Wiecha, Aurélien Cuche +11
Silicon-based dielectric nanoantennas provide an effective platform for engineering light-matter interactions in van der Waals semiconductors. Here, we demonstrate near-field coupl…
Measurement of Conduction and Valence Bands g-factors in a Transition Metal Dichalcogenide Monolayer
Cedric Robert, Hanan Dery, Lei Ren +9
The electron valley and spin degree of freedom in monolayer transition-metal dichalcogenides can be manipulated in optical and transport measurements performed in magnetic fields.…
Controlling interlayer excitons in MoS2 layers grown by chemical vapor deposition
Ioannis Paradisanos, Shivangi Shree, Antony George +9
Combining MoS monolayers to form multilayers allows to access new functionalities. In this work, we examine the correlation between the stacking order and the interlayer coupli…
Relaxation and darkening of excitonic complexes in electrostatically-doped monolayer semiconductors: Roles of exciton-electron and trion-electron interactions
Min Yang, Lei Ren, Cedric Robert +5
We present photoluminescence measurements in monolayer WSe, which point to the importance of the interaction between charged particles and excitonic complexes. The theoretical…
Laser patterning of the room temperature van der Waals ferromagnet 1-CrTe
Tristan Riccardi, Suman Sarkar, Anike Purbawati +19
Lamellar crystalline materials, whose layers are bond by van der Waals forces, can be stacked to form ultrathin artificial heterostructures, and in particular vertical magnetic jun…
Spin/Valley pumping of resident electrons in WSe2 and WS2 monolayers
Cedric Robert, Sangjun Park, Fabian Cadiz +14
Monolayers of transition metal dichalcogenides are ideal materials to control both spin and valley degrees of freedom either electrically or optically. Nevertheless, optical excita…
Filtering the photoluminescence spectra of atomically thin semiconductors with graphene
Etienne Lorchat, Luis E. Parra López, Cédric Robert +6
Atomically thin semiconductors made from transition metal dichalcogenides (TMDs) are model systems for investigations of strong light-matter interactions and applications in nanoph…
Identifying optical signatures of momentum-dark excitons in transition metal dichalcogenide monolayers
Jessica Lindlau, Cedric Robert, Victor Funk +12
Transition metal dichalcogenide (TMD) monolayers (MLs) exhibit rich photoluminescence spectra associated with interband optical transitions of direct-gap semiconductors. Upon absor…
Carrier and Spin Coherent Dynamics in Strained Germanium-Tin Semiconductor on Silicon
Sebastiano De Cesari, Andrea Balocchi, Elisa Vitiello +6
Germanium-Tin is emerging as a material exhibiting excellent photonic properties. Here we demonstrate optical initialization and readout of spins in this intriguing group IV semico…
Excitons in atomically thin transition metal dichalcogenides
Gang Wang, Alexey Chernikov, Mikhail M. Glazov +4
Atomically thin materials such as graphene and monolayer transition metal dichalcogenides (TMDs) exhibit remarkable physical properties resulting from their reduced dimensionality…
Guide to optical spectroscopy of layered semiconductors
Shivangi Shree, Ioannis Paradisanos, Xavier Marie +2
In this technical review we give an introduction to optical spectroscopy for layered materials as a powerful, non-invasive tool to access details of the electronic band structure a…
Impact of heavy hole-light hole coupling on optical selection rules in GaAs quantum dots
Thomas Belhadj, Thierry Amand, Alejandro Kunold +8
We report strong heavy hole-light mixing in GaAs quantum dots grown by droplet epitaxy. Using the neutral and charged exciton emission as a monitor we observe the direct consequenc…
Thermal assisted transport of biexcitons in monolayer WSe2
Dorian Béret, Louka Hemmen, Vishwas Jindal +9
Studies of excitonic transport in transition metal dichalcogenide monolayers have attracted increasing interest in recent years in order to develop nano-optoelectronic devices made…
Kapitza-resistance-like exciton dynamics in atomically flat MoSe-WSe lateral heterojunction
Hassan Lamsaadi, Dorian Beret, Ioannis Paradisanos +13
Being able to control the neutral excitonic flux is a mandatory step for the development of future room-temperature two-dimensional excitonic devices. Semiconducting Monolayer Tran…
Sub-nm range momentum-dependent exciton transfer from a 2D semiconductor to graphene
Aditi Raman Moghe, Delphine Lagarde, Sotirios Papadopoulos +11
Heterostructures made from atomically thin semiconductors (here MoSe) and graphene are uniquely poised to investigate photoinduced charge and energy transfer in the 2D limit. H…
Fine Structure and Lifetime of Dark Excitons in Transition Metal Dichalcogenide Monolayers
Cedric Robert, Thierry Amand, Fabian Cadiz +7
The intricate interplay between optically dark and bright excitons governs the light-matter interaction in transition metal dichalcogenide monolayers. We have performed a detailed…
Alloy engineering of excitonic properties in TMD monolayers
Eirini Katsipoulaki, Adlen Smiri, Panagiotis Spiliotakis +12
We investigate monolayer MoSSe alloys across the full composition range using optical spectroscopy. We demonstrate continuous tuning of the optical gap over $\sim…
Exciton spectroscopy and diffusion in MoSe2-WSe2 lateral heterostructures encapsulated in hexagonal boron nitride
Dorian Beret, Ioannis Paradisanos, Ziyang Gan +17
Chemical vapor deposition (CVD) allows lateral edge epitaxy of transition metal dichalcogenide heterostructures with potential applications in optoelectronics. Critical for carrier…
Well separated trion and neutral excitons on superacid treated MoS2 monolayers
Fabian Cadiz, Simon Tricard, Maxime Gay +6
Developments in optoelectronics and spin-optronics based on transition metal dichalcogenide monolayers (MLs) need materials with efficient optical emission and well-defined transit…
Discrete quantum dot like emitters in monolayer MoSe2: Spatial mapping, Magneto-optics and Charge tuning
Artur Branny, Gang Wang, Santosh Kumar +5
Transition metal dichalcogenide monolayers such as MoSe2,MoS2 and WSe2 are direct bandgap semiconductors with original optoelectronic and spin-valley properties. Here we report spe…
Spin-orbit engineering in transition metal dichalcogenide alloy monolayers
Gang Wang, Cedric Robert, Aslihan Suslu +8
Transition metal dichalcogenide (TMDC) monolayers are newly discovered semiconductors for a wide range of applications in electronics and optoelectronics. Most studies have focused…
Giant Stark splitting of an exciton in bilayer MoS
Nadine Leisgang, Shivangi Shree, Ioannis Paradisanos +10
Transition metal dichalcogenides (TMDs) constitute a versatile platform for atomically thin optoelectronics devices and spin-valley memory applications. In monolayers optical absor…
Interlayer exciton mediated second harmonic generation in bilayer MoS2
Shivangi Shree, Delphine Lagarde, Laurent Lombez +10
Second harmonic generation (SHG) is a non-linear optical process, where two photons coherently combine into one photon of twice their energy. Efficient SHG occurs for crystals with…
Dependence of the hBN Layer Thickness on the Band Structure and Exciton Properties of Encapsulated WSe2 Monolayers
Iann C. Gerber, Xavier Marie
The optical properties of two-dimensional transition metal dichalcogenide monolayers such as MoS or WSe are dominated by excitons, Coulomb bound electron-hole pairs. Screen…
Direct measurement of the lifetime and coherence time of Cu2O Rydberg excitons
Poulab Chakrabarti, Kerwan Morin, Delphine Lagarde +2
Rydberg states of excitons are promising quantum objects to engineer giant nonlinearities in a solid-state system. For this purpose, a deeper understanding of the dynamics of Rydbe…
Synthesis of Highly Anisotropic Semiconducting GaTe Nanomaterials and Emerging Properties Enabled by Epitaxy
Hui Cai, Bin Chen, Gang Wang +7
Pseudo-one dimensional (pseudo-1D) materials are a new-class of materials where atoms are arranged in chain like structures in two-dimensions (2D). Examples include recently discov…
Second harmonic generation control in twisted bilayers of transition metal dichalcogenides
Ioannis Paradisanos, Andres Manuel Saiz Raven, Thierry Amand +7
The twist angle in transition metal dichalcogenide (TMD) heterobilayers is a compelling degree of freedom that determines electron correlations and the period of lateral confinemen…
Electron and hole doping of monolayer WSe2 induced by twisted ferroelectric hexagonal boron nitride
Jules Fraunié, Rayan Jamil, Richard Kantelberg +12
For the past few years, 2D ferroelectric materials have attracted strong interest for their potential in future nanoelectronics devices. The recent discovery of 2D ferroelectricity…
Charge state tuning of spin defects in hexagonal boron nitride
Jules Fraunié, Tristan Clua-Provost, Sébastien Roux +14
Boron vacancies in hexagonal boron nitride (hBN) are among the most extensively studied optically active spin defects in van der Waals crystals, due to their promising potential to…
High luminescence efficiency of multi-valley excitonic complexes in heavily doped WSe2 monolayer
Sébastien Roux, Tilly Guyot, Abraao Cefas Torres-Dias +9
Monolayers of group-VI transition-metal dichalcogenides (TMDs) are two-dimensional semiconductors that exhibit exceptionally strong light-matter coupling yet typically suffer from…
One pot chemical vapor deposition of high optical quality large area monolayer Janus transition metal dichalcogenides
Ziyang Gan, Ioannis Paradisanos, Ana Estrada-Real +13
We report one-pot chemical vapor deposition (CVD) growth of large-area Janus SeMoS monolayers, with the asymmetric top (Se) and bottom (S) chalcogen atomic planes with respect to t…
Nuclear spin physics in quantum dots: an optical investigation
Bernhard Urbaszek, Xavier Marie, Thierry Amand +5
The mesoscopic spin system formed by the 10E4-10E6 nuclear spins in a semiconductor quantum dot offers a unique setting for the study of many-body spin physics in the condensed mat…
Capacitively-coupled and inductively-coupled excitons in bilayer MoS
Lukas Sponfeldner, Nadine Leisgang, Shivangi Shree +10
The interaction of intralayer and interlayer excitons is studied in a two-dimensional semiconductor, homobilayer MoS. It is shown that the measured optical susceptibility revea…
Quantum light generation with ultra-high spatial resolution in 2D semiconductors via ultra-low energy electron irradiation
Ajit Kumar Dash, Sharad Kumar Yadav, Sebastien Roux +7
Single photon emitters (SPEs) are building blocks of quantum technologies. Defect engineering of 2D materials is ideal to fabricate SPEs, wherein spatially deterministic and qualit…
Mo Thio and Oxo-Thio Molecular Complexes Film as Self-Healing Catalyst for Photocatalytic Hydrogen Evolution on 2D Materials
Juliana Barros Barbosa, Pierre Louis Taberna, Valerie Bourdon +10
2D semiconducting nanosheets of Transition Metal Dichalcogenides are attractive materials for solar energy conversion because of their unique absorption properties. Here, we propos…
Efficient phonon cascades in hot photoluminescence of WSe monolayers
Ioannis Paradisanos, Gang Wang, Evgeny M. Alexeev +5
Energy relaxation of photo-excited charge carriers is of significant fundamental interest and crucial for the performance of monolayer (1L) transition metal dichaclogenides (TMDs)…
Phonon-assisted Photoluminescence from Dark Excitons in Monolayers of Transition Metal Dichalcogenides
Samuel Brem, August Ekman, Dominik Christiansen +7
The photoluminescence (PL) spectrum of transition metal dichalcogenides (TMDs) shows a multitude of emission peaks below the bright exciton line and not all of them have been expla…
Exciton Spin Dynamics in Semiconductor Quantum Wells
Thierry Amand, Xavier Marie
In this paper we will review Exciton Spin Dynamics in Semiconductor Quantum Wells. The spin properties of excitons in nanostructures are determined by their fine structure. We will…
Using Light to Polarize and Detect Electron Spins in Silicon
Xavier Marie, Delphine Lagarde, Andrea Balocchi +5
Despite decades of research, demonstration of all-optical detection and control of free electron spins in silicon remains elusive. Here, we directly probe the electron spin propert…
Gate-tuneable single-photon emitters in WSe2 monolayer created via AFM nanoindentation on rigid SiO2/Si substrates
Ajit Kumar Dash, Sanket Jugade, Manavendra Pratap Singh +12
Single-photon emitters (SPEs) hosted by two-dimensional (2D) semiconducting materials are envisioned for next-generation quantum applications. However, SPE creation in 2D semicondu…
Non-radiative energy transfer between boron vacancies in hexagonal boron nitride and other 2D materials
Fraunié Jules, Mikhail M. Glazov, Sébastien Roux +13
Boron vacancies () in hexagonal boron nitride (hBN) have emerged as a promising platform for two-dimensional quantum sensors capable of operating at atomic-scale proximity.…
Accessing high optical quality of MoS2 monolayers grown by chemical vapor deposition
Shivangi Shree, Antony George, Tibor Lehnert +9
Chemical vapor deposition (CVD) allows growing transition metal dichalcogenides (TMDs) over large surface areas on inexpensive substrates. In this work, we correlate the structural…
Probing the optical near-field interaction of Mie nanoresonators with atomically thin semiconductors
Ana Estrada-Real, Ioannis Paradisanos, Peter R. Wiecha +10
Optical Mie resonators based on silicon nanostructures allow tuning of light-matter-interaction with advanced design concepts based on CMOS compatible nanofabrication. Optically ac…
Spin-injection and spin-relaxation in p-doped InGaAs/GaAs quantum-dot spin light emitting diode at zero magnetic field
Alaa E. Giba, Xue Gao, Mathieu Stoffel +10
We report on efficient spin injection in p-doped InGaAs/GaAs quantum-dot (QD) spin light emitting diode (spin-LED) under zero applied magnetic field. A high degree of electrolumine…
Optical orientation of electron spins and valence band spectroscopy in germanium
Fabio Pezzoli, Andrea Balocchi, Elisa Vitiello +2
We have investigated optical orientation in the vicinity of the direct gap of bulk germanium. The electron spin polarization is studied via polarization-resolved photoluminescence…
Energy shifts and broadening of excitonic resonances in electrostatically-doped semiconductors
Hanan Dery, Cedric Robert, Scott A. Crooker +2
Tuning the density of resident electrons or holes in semiconductors provides crucial insight into the composition of excitonic complexes that are observed as absorption or photolum…
Exciton valley depolarization in monolayer transition-metal dichalcogenides
Min Yang, Cedric Robert, Zhengguang Lu +4
The valley degree of freedom is a sought-after quantum number in monolayer transition-metal dichalcogenides. Similar to optical spin orientation in semiconductors, the helicity of…
Optical detection of long electron spin transport lengths in a monolayer semiconductor
Lei Ren, Laurent Lombez, Cedric Robert +8
Using a spatially-resolved optical pump-probe experiment, we measure the lateral transport of spin/valley polarized electrons over very long distances (tens of micrometers) in a si…
Optically monitored nuclear spin dynamics in individual GaAs quantum dots grown by droplet epitaxy
Thomas Belhadj, Takashi Kuroda, Claire-Marie Simon +6
We report optical orientation experiments in individual, strain free GaAs quantum dots in AlGaAs grown by droplet epitaxy. Circularly polarized optical excitation yields strong cir…
Investigation of the anisotropic electron g factor as a probe of the electronic structure of GaBiAs/GaAs epilayers
Christopher A. Broderick, Simone Mazzucato, Hélène Carrère +9
The electron Landé g factor () is investigated both experimentally and theoretically in a series of GaBiAs/GaAs strained epitaxial layers, for bismuth composi…
From the synthesis of hBN crystals to their use as nanosheets for optoelectronic devices
Camille Maestre, Yangdi Li, Vincent Garnier +11
In the wide world of 2D materials, hexagonal boron nitride (hBN) holds a special place due to its excellent characteristics. In addition to its thermal, chemical and mechanical sta…