Pierre Verlot (ILM, Lyon)
Séminaire le 12/07 à 14h (Bâtiment 5 salle 5.201)
l’Optomécanique Quantique
Quantum optomechanics at room temperature: A nanomechanical endeavour?


Optomechanics is the field investigating the reciprocal interaction between electromagnetic and mechanical degrees of freedom1.

Recently, impressive progress has been accomplished in the field, notably with the demonstration of multiple systems operating in the quantum regime of the
optomechanical interaction2–4. This in great part relies on the extreme miniaturization of the mechanical devices, which enables drastic decrease of the thermal noise, at the benefit of quantum effects5,6.

So far however, the quantum regime of the optomechanical interaction has essentially been evidenced at liquid helium temperature or below and remains remote to ambient conditions. In this talk, I will present novel approaches raising the realistic perspective of operating optomechanical systems deep in the quantum regime and at room temperature. I will primarily focus on the fabrication and optomechanical characterization of a novel hybrid carbon nanotube-based approach7–9 which is found to a record low thermal force noise at room temperature, while fully preserving sensing capabilities. I will also discuss the role of non-linearities and corresponding sensing limitations for the sensitivity of
those devices at ambient temperature. Last, I will introduce recent results on a novel quantum hybrid optomechanical approach, based on the use of gram-scale rare-earth ion doped crystal10,11, which appears very promising as for reaching the quantum regime at room temperature and under very robust conditions12.

References
1. Aspelmeyer, M., Kippenberg, T. J. & Marquardt, F. Cavity optomechanics. Reviews of Modern Physics 86,1391,(2014).
2. Chan, J. et al. Laser cooling of a nanomechanical oscillator into its quantum ground state. Nature 478, 89–92 (2011).
3. Purdy, T. P., Peterson, R. W. & Regal, C. A. Observation of radiation pressure shot noise on a macroscopic object. Science 339, 801–804 (2013).
4. Riedinger, R. et al. Remote quantum entanglement between two micromechanical oscillators. Nature 556, 473–477 (2018).
5. Moser, J. et al. Ultrasensitive force detection with a nanotube mechanical resonator. Nature
nanotechnology 8, 493–496 (2013).
6. Moser, J., Eichler, A., Güttinger, J., Dykman, M. I. & Bachtold, A. Nanotube mechanical resonators with quality factors of up to 5 million. Nature nanotechnology 9, 1007–1011 (2014).
7. Tsioutsios, I., Tavernarakis, A., Osmond, J., Verlot, P. & Bachtold, A. Real-time measurement of nanotube resonator fluctuations in an electron microscope. Nano letters 17, 1748–1755 (2017).
8. Tavernarakis, A. et al. Optomechanics with a hybrid carbon nanotube resonator. Nature communications 9, 1–8 (2018).
9. Gruber, G. et al. Mass sensing for the advanced fabrication of nanomechanical resonators. Nano letters 19, 6987–6992 (2019).
10. Louchet-Chauvet, A., Ahlefeldt, R. & Chanelière, T. Piezospectroscopic measurement of high-frequency vibrations in a pulse-tube cryostat. Review of Scientific Instruments 90, 034901 (2019).
11. Louchet-Chauvet, A. & Chanelière, T. Limits to the sensitivity of a rare-earth-enabled cryogenic vibration sensor. arXiv preprint arXiv:2112.03713 (2021).
12. Louchet-Chauvet, A., Verlot, P., Poizat, J.-P. & Chanelière, T. Optomechanical backaction processes in a bulk rare-earth doped crystal. arXiv preprint arXiv:2109.06577 (2021).

Buiding up hierarchical organizations is still challenging because one have to design self-assembly mechanismes at various length scales and with similar time scales. Two nanoparticle systems are presented. The former system (Fig. 1) is a interplaying between drying processes at nanometric scale (colloidal crystallization) and millimetric scale (Maze Formation within micropatterned surfaces). The second system is the slow crystalisation of polydisperse Ludox®. In both cases, entropy plays an important role with (i) Onsager “Forces” that ease the nematic order between nanorods, and with (ii) mixing entropy in cluster phases.
The former system can be exploited to generate well defined hierarchical organizations with new photophysical properties (superradiance). The Laves phase (Fig. 2) observed in the second system is only the first generation of a clustering process that can generate BCC and AB13 phases of rhombicuboctahedron with more than 500 nanoparticles per unit cell.

Keywords: nanoparticles superlatices, Onsager, mixing entropy, drying, crystallization tolerance.
References
[1] Hamon, et al, ACS. Nano, 2012, 6(5), 4137-4146. Bizien, et al, Small, 2014, 10(18), 3707–3716. Panizza, et al, Phys. Rev. Lett. 2018 121(20), 078002.. Bizien, et al, J. Nanomaterials, 2021, 1790976.
[2] Cabane, et al, Phys. Rev. Lett. 2016, 116(20), 208001. Botet, et al, Faraday Dis., 2016, 186, 229-240. Unpublished Results.

MassTech Collaborative has helped to make the Commonwealth a beacon for advanced manufacturing. In partnership with the AIM Photonics manufacturing institute, MassTech has launched five Laboratories for Education and Application Prototypes (LEAPs) within academic institutions spread widely across Massachusetts, to develop a skilled workforce in integrated photonics. Hands-on and in-person workshops, bootcamps and laboratory courses are offered at these LEAPs to learners from academia, industry, and the government.



In addition to teaching how to test Photonic Integrated Circuits (PICs), each LEAP has a specialized focus. The LEAP @ Massachusetts Institute of Technology focuses on Electronic-Photonic Packaging (EPP), the LEAP @ Worcester Polytechnic Institute – Quinsigamond Community College (WPI-QCC) on bio-medical photonics applications, LEAP @ Stonehill College on materials testing and photodetectors, LEAP@ Bridgewater State University (BSU) on high power and ultrafast near- and mid-infrared lasers and quantum-devices, and finally the LEAP @ Western New England (WNE) University on lasers and RF photonics.

In this talk I will focus on the LEAP at BSU and some of the research and opportunities we could offer to colleagues in Montpellier in research, pedagogical strategies and opportunities and ideas with industry prototyping. In particular, I will present some of the work we have been doing to characterize the nonlinear third order coefficients in waveguide structures (fibers and photonic integrated circuits). The technique, called D-Scan (dispersive scan) uses the temporal analogous of the Z-Scan, treating the waveguides as temporal lenses, and consists in measuring the output spectral broadening of transmitted pulses for various dispersion coefficients φ (2) applied to the injected pulses.

Abstract Clascidia Furtado: The possibility of manipulating matter and controlling processes at the nanoscale, which overlaps the scale of biological structures and processes, has brought unprecedented advances in nanobiotechnologies. An example is the construction of multifunctional nanoplatforms, with special attention to those based on carbon nanostructures (nanotubes and graphenes) containing biomolecules (proteins, peptides, nucleic acids) or drugs anchored on their surface. They can outperform conventional molecular compounds due to their high reactivity and ability to undergo multiple functionalizations, generating technological solutions with high sensitivity, specificity and selectivity. In this talk, we will describe our group's efforts to 1) carefully obtain nanocarbon-protein/aptamer platforms for vaccine formulations and biosensors with response and diagnostic potential for cancer; and 2) understand nanomaterial-biomolecule interactions.

Abstract Aldo Zarbin: This talk will demonstrate the huge potentiality coming from the interface between immiscible liquids to synthesize, stabilize and process complex materials as transparent and conductive thin films to be applied in different technological systems and devices. Examples of multicomponent materials combining carbon nanostructures (nanotubes, graphene), 2D materials, Prussian blue analogues, metal nanoparticles and conducting polymers will be presented, highlighting unique preparative routes, characterization techniques, study of properties and the structure/properties relationship, thin film deposition over several solid substrates and application in transparent aqueous metal-ion batteries; flexible supercapacitors; electrochromic devices; solar cells; as transparent electrodes and as catalysts.

Vitrimers are now commonly considered as the third class of polymer materials alongside thermoplastics and thermosets. At service temperature, vitrimers behave like traditional thermosets, with good mechanical characteristics but can be recycled, reshaped at high temperature similarly to glass. This discovery opens new green perspectives such as crack repairing, correction of moulding defects and depolymerisation/recycling using soft conditions. Nonetheless, the transfer from academia toward industry is not straigthforward and require extensive collaborative efforts from scientists and engineers in chemistry, materials science and engineering.

Confinement and photocatalysis in geo-inspired nanotubes
Erwan Paineau* and Pascale Launois

Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France

*erwan-nicolas.paineau@universite-paris-saclay.fr
Hollow cylinders with a diameter in the nanometer range are carving out prime positions in nanosciences. Thanks to their physico-chemical properties, they could be key elements for next-generation nanofluidics devices, for selective molecular sieving, energy conversion or as catalytic nanoreactors. Some challenges such as diameter and interface control are solved for imogolite nanotubes (INTs). Belonging to clay minerals, imogolite exists in its natural state but is widely dispersed in environment, limiting its applications. The major breakthrough for using INTs was certainly their synthesis by sol-gel methods under mild conditions.
We will first focus here on the recent developments of INT synthesis, particularly in terms of morphological control and surface functionalization [1]. We will show that it is now possible designing innovative geo-inspired INTs with modular interfaces in a predictive way [2], which has recently led to some progress in the field of imogolite-based functional materials [3]. We will also prove that this system is ideal to investigate the structure and dynamics of water in interaction with the nanotube walls [4,5]. Finally, we will demonstrate that these nanotubes could be considered as potential photoactive nanoreactors, thanks to a unique polarization effect of their walls.

References
[1] M.S. Amara et al., Chem. Mater. (2015) 27, 1488; Paineau et al., J. Coll. Inter. Sci. (2020), 580, 275
[2] G. Monet et al., Nat. Commun. (2018), 9, 2033
[3] W.J. Lee et al., ACS Nano (2020), 14, 5570
[4] G. Monet et al., Nanoscale Adv. (2020), 2, 1869
[5] G. Martin-Gassin et al., J. Phys. Chem. Letters (2022), 13, 6883

In this seminar, I will present our recent discovery of graphene's electroluminescence in the middle infrared.

Electroluminescence is the phenomenon by which a material emits light in response to the passage of an electrical current. In solids, it is the prerogative of semiconductors and related organic materials, and it results from the radiative recombination of electrons and holes.

We study high mobility graphene field effect transistors at room temperature and ambient conditions. These transistors are made of a monolayer graphene flake encapsulated in a hexagonal Boron nitride insulator. When submitted to a large bias, we observe the appearance of a sharp emission peak at a photon energy of 190meV in the far field e.m. radiation of the transistor. Using a series of test experiments, we demonstrate the electroluminescent nature of this emission.

The semi-metallic nature of graphene a priori forbids electroluminescence: Indeed, in semiconductors, the bandgap energetically insulates the electrons from the holes. Such protection doesn’t exist in graphene which is gapless. Nonetheless, electroluminescence is possible, because (i) of the remarkable inefficiency of the non-radiative carrier relaxation in graphene, and (ii) thanks to an original carrier injection mechanism specific to 2D semimetals: the Zener-Klein (ZK) tunnel conductance.
Using electronic noise thermometry experiments, we observe that the electroluminescence of graphene is signaled by a strong cooling of the electron gas at large bias; an effect well known in regular electroluminescent devices near the electroluminescent threshold. I will discuss the microscopic mechanisms at stake and show that the properties of hexagonal Boron nitride plays a key role in this radiative heat exchange, and this can be used to tune the cooling efficiency.