Optical Detection of Sliding Ferroelectric Switching in hBN with a WSe Monolayer.

When two BN layers are stacked in parallel in an AB or BA arrangement, a spontaneous out-of-plane electric polarization arises due to charge transfer in the out-of-plane B-N bonds. The ferroelectric switching from AB to BA (or BA to AB) can be achieved with a relatively small out-of-plane electric field through the in-plane sliding of one atomic layer over the other. However, the optical detection of such ferroelectric switching in hBN has not yet been demonstrated.

Impact of French lockdowns on bereavement experiences: Insight from ALCESTE analysis revealing psychological resilience and distinct grief dynamics amidst COVID-19.

At the beginning of 2020, the entire world was shocked by a global health emergency. According to the literature, fear, high mortality and health restrictions had significant psychological consequences on the population. This study evaluates the French lockdown's impact on the grieving process and how people worked through their grief.

The Absence of Funeral Rites as a Risk Factor for the French Bereaved Population.

During the COVID-19 pandemic, stringent measures were imposed in numerous countries, including France. These measures significantly disrupted societal practices, particularly mourning and funeral rituals. This study, conducted between June and September 2021 as part of the COVIDEUIL-France research, involved 242 participants, predominantly female (84%) with an average age of 49.

Direct patterning of nanoparticles and biomolecules by liquid nanodispensing.

We report on the localized deposition of nanoparticles and proteins, nano-objects commonly used in many nanodevices, by the liquid nanodispensing (NADIS) technique which consists in depositing droplets of a solution through a nanochannel drilled at the apex of an AFM tip. We demonstrate that the size of spots can be adjusted from microns down to sub-50 nm by tuning the channel diameter, independently of the chemical nature of the solute. In the case of nanoparticles, we demonstrated the ultimate limit of the method and showed that large arrays of single (or pairs of) nanoparticles can be reproducibly deposited.

Ultrasensitive magnetometers based on carbon-nanotube mechanical resonators.

We describe herein how a nanoelectromechanical system based on a carbon nanotube used as a force sensor can enable one to assess the magnetic properties of a single and very small nano-object grafted onto the nanotube. Numerical simulations performed within the framework of the Euler-Bernoulli theory of beams predict that the magnetic field dependence of the nanotube mechanical resonance frequency is a direct probe for the nano-object magnetic properties and that a sensitivity around a few (few hundreds) Bohr magnetic moments at low temperature (room temperature) can be expected.

Coupling mechanics to charge transport in carbon nanotube mechanical resonators.

Nanoelectromechanical resonators have potential applications in sensing, cooling, and mechanical signal processing. An important parameter in these systems is the strength of coupling the resonator motion to charge transport through the device. We investigated the mechanical oscillations of a suspended single-walled carbon nanotube that also acts as a single-electron transistor.

Ultrasensitive mass sensing with a nanotube electromechanical resonator.

Shrinking mechanical resonators to submicrometer dimensions (approximately 100 nm) has tremendously improved capabilities in sensing applications. In this Letter, we go further in size reduction using a 1 nm diameter carbon nanotube as a mechanical resonator for mass sensing. The performances, which are tested by measuring the mass of evaporated chromium atoms, are exceptional.

Onset of landau-level formation in carbon-nanotube-based electronic Fabry-Perot resonators.

We report on the onset of Landau-level formation in a carbon nanotube-based Fabry-Perot resonator. Supported by excellent agreement between calculated and measured magnetoconductance patterns, the applied perpendicular magnetic field is shown to modulate the Fabry-Perot conductance oscillations consistently with the formation of a Landau level in the 1D massless Dirac fermions particle excitations.

Imaging mechanical vibrations in suspended graphene sheets.

We carried out measurements on nanoelectromechanical systems based on multilayer graphene sheets suspended over trenches in silicon oxide. The motion of the suspended sheets was electrostatically driven at resonance using applied radio frequency voltages. The mechanical vibrations were detected using a novel form of scanning probe microscopy, which allowed identification and spatial imaging of the shape of the mechanical eigenmodes.

Aharonov-Bohm conductance modulation in ballistic carbon nanotubes.

We report on magnetoconductance experiments in ballistic multiwalled carbon nanotubes threaded by magnetic fields as large as 55 T. In the high temperature regime (100 K), giant modulations of the conductance, mediated by the Fermi level location, are unveiled. The experimental data are consistently analyzed in terms of the field-dependent density of states of the external shell that modulates the injection properties at the electrode-nanotube interface, and the resulting linear conductance.

Gate-dependent magnetoresistance phenomena in carbon nanotubes.

We report on the first experimental study of the magnetoresistance of double-walled carbon nanotubes under a magnetic field as large as 50 T. By varying the field orientation with respect to the tube axis, or by gate-mediated shifting the Fermi level position, evidence for unconventional magnetoresistance is presented and interpreted by means of theoretical calculations.