Papers by Yannick Chassagneux
Situees entre l'infrarouge et les micro-ondes, les ondes dites "terahertz" (THz) on... more Situees entre l'infrarouge et les micro-ondes, les ondes dites "terahertz" (THz) ont les proprietes de passer aussi bien a travers la peau et les vetements que les papiers, le bois, le carton ou encore le plastique. Autant d'atouts qui permettent d'envisager de multiples applications dans les secteurs de l'imagerie medicale, de la spectroscopie, de la securite et de l'environnement. D'ou l'interet que suscitent les lasers a cascade quantique terahertz, une recente famille de lasers semi-conducteurs qui emettent a des frequences de l'ordre du terahertz. Pourtant, s'ils sont aujourd'hui les seules sources compactes fonctionnant dans cette gamme de frequences, ils presentent deux inconvenients : Premierement, ils ne fonctionnent qu'a des temperatures cryogeniques. En vue d'une augmentation future de la temperature maximale de fonctionnement (Tmax), nous avons developpe une etude comparative en fonction de la fre- quence d'em...
ECS Meeting Abstracts, 2021
In the last decades, research on graphene has been extensively developed. It is now well establis... more In the last decades, research on graphene has been extensively developed. It is now well established that graphene shows unique physical properties such as extremely high charge-carrier mobility, which promises a wealth of applications in (nano)electronics. However, graphene does not have a bandgap. Therefore, one challenge for scientists is the control and modification of the electronic porperties in order to open a sizable bandgap. In this context nanosized graphene have a lot of assets. The reduction of one dimension of graphene leads to carbon nanotubes (CNT) or graphene nanoribbons (GNRs) while the reduction of the two dimensions leads to graphene quantum dots (GQDs). The size reduction, the topology and the shape of the edges define the electronic and optical properties of this family of objects. In this presentation, I will show our last results on the photophysics of such nanostructures investigated at the single object level.
arXiv: Quantum Physics, 2017
A scheme for strong coupling between a single atomic spin and the torsional mode of levitating na... more A scheme for strong coupling between a single atomic spin and the torsional mode of levitating nanoparticles is proposed. The idea is based on spin read-out of NV centers embedded in aspherical nanodiamonds levitating in an ion trap. We show that the torsional mode of nanodiamonds can be strongly coupled to the electronic spin of the NV center using a homogeneous transverse magnetic field. Further, we demonstrate that cooling to the torsional ground state can be performed efficiently using a combination of microwaves and weak optical pulses at room temperature.
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Optical properties of core-shell systems based on carbon nanotubes Lucile Orcin-Chaix, Yannick Chassagneux, Christophe Voisin, Stéphane Campidelli, Jean-Sébastien Lauret
ACS Applied Nano Materials
In the spirit of the core–shell approach that made it possible to greatly enhance the photostabil... more In the spirit of the core–shell approach that made it possible to greatly enhance the photostability of semiconductor nanoparticles, we study the emission stability of single carbon nanotubes prote...
Physical Review B, May 21, 2018
We develop a theoretical frame to investigate the spectral dependence of the brightness of a sing... more We develop a theoretical frame to investigate the spectral dependence of the brightness of a singlephoton source made of a solid-state nano-emitter embedded in a high-quality factor micro-cavity. This study encompasses the cases of localized excitons embedded in a one (1D), two (2D) or threedimensional (3D) matrix. The population evolution is calculated based on a spin-boson model, using the non-interacting blip approximation (NIBA). We find that the spectral dependence of the singlephoton source brightness (hereafter called spectral efficiency) can be expressed analytically through the free-space emission and absorption spectra of the emitter, the vacuum Rabi splitting and the loss rates of the system. In other words, the free-space spectrum of the emitter encodes all the relevant information on the interaction between the exciton and the phonon bath to obtain the dynamics of the cavity coupled system. We compute numerically the spectral efficiency for several types of localized emitters differing by the phonon bath dimentionality. In particular, in low-dimensional systems where this interaction is enhanced, a pronounced asymmetric energy exchange between the emitter and the cavity on the phonon side-bands yields a considerable extension of the tuning range of the source through phonon-assisted cavity feeding, possibly surpassing that of a purely resonant system.
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Papers by Yannick Chassagneux