arXiv subjects

Nicolas Clément

Publications and source records attributed to Nicolas Clément.

3 recordsLinked to original sources

arXiv2026

Room-temperature 1/3 suppression of diffusive shot noise

Diffusive conductors share a universal shot noise reduction of 1/3. This result can be obtained from quantum scattering, Boltzmann-Langevin kinetics, or by symmetric simple exclusion process, but experiments have been limited to cryogenic conditions and the understanding of this universality remains incomplete. Here we show that ferrocene redox cycling in a microfluidic gap is room temperature realization of this universality. An analytical model of the current and its noise is derived and confirmed experimentally. The universal 1/3 shot noise suppression is recovered in the diffusion-limited regime, providing a bridge between mesoscopic physics and electrochemistry, opening a new route for probing molecular dynamics through room-temperature noise measurements.

cond-mat.mes-hall↗

arXiv2020

Attoampere Nanoelectrochemistry

Local electrochemical measurements and imaging at the nanoscale are crucial for the future development of molecular devices, sensors, materials engineering, electrophysiology and various energy applications from artificial photosynthesis to batteries. The ultimate step towards single-molecule sensitivity requires the measurement of aA currents, which is three orders of magnitude below that of current state-of-the-art measurement abilities. Here, we show electrochemical measurements at the sub aA level and <80 nm spatial resolution, that we reach by exploiting the ultra-high sensitivity of our GHz microscope for local faradaic interface capacitances. We demonstrate this for a well-known surface-bound ferrocene alkyl monolayer, a system that cannot be studied at the nanoscale unless large nanoarrays are used11. We report the simultaneous measurement of local cyclic voltammograms (CV) which provide atomistic information on the respective electron transfer reaction and reveal two molecular configurations with a similar redox energy potential -- insights inaccessible by electrochemical ensemble measurements.

physics.chem-ph↗

arXiv2010

1/f Tunnel Current Noise through Si-bound Alkyl Monolayers

We report low frequency tunnel current noise characteristics of an organic monolayer tunnel junction. The measured devices, n-Si/alkyl chain (C18H37)/Al junctions, exhibit a clear 1/ f^y power spectrum noise with 1< y <1.2. We observe a slight bias dependent background of the normalized current noise power spectrum (SI/I^2). However, a local increase is also observed over a certain bias range, mainly if V > 0.4 V, with an amplitude varying from device to device. We attribute this effect to an energy-dependent trap-induced tunnel current. We find that the background noise, SI, scales with (\partial I/\partial V)^2 . A model is proposed showing qualitative agreements with our experimental data.

cond-mat.mes-hall↗