Two-dimensional systems can host exotic particles called anyons whose quantum statistics are neither bosonic nor fermionic. For example, the elementary excitations of the fractional quantum Hall effect at filling factor ν = 1/m (where m is an odd integer) have been predicted to obey abelian fractional statistics, with a phase ϕ associated with the exchange of two particles equal to π/m. However, despite numerous experimental attempts, clear signatures of fractional statistics remain elusive. Here we experimentally demonstrate abelian fractional statistics at filling factor ν = 1/3 by measuring the current correlations resulting from the collision between anyons at a beam-splitter. By analyzing their dependence on the anyon current impinging on the splitter and comparing with recent theoretical models, we extract ϕ = π/3, in agreement with predictions. arXiv:2006.13157v1 [cond-mat.mes-hall]

Nanomechanical resonators are used with great success to couple mechanical motion to other degrees of freedom, such as photons, spins, and electrons [1,2]. Mechanical vibrations can be efficiently cooled and amplified using photons, but not with other degrees of freedom. Here, we demonstrate a simple yet powerful method for cooling, amplification, and self-oscillation using electrons. This is achieved by applying a constant (DC) current of electrons through a suspended nanotube in a dilution fridge.We demonstrate cooling down to 4.6 ± 2.0 quanta of vibrations. We also observe selfoscillation, which can lead to prominent instabilities in the electron transport through the nanotube. We attribute the origin of the observed cooling and self-oscillation to an electrothermal effect. This work shows that electrons may become a useful resource for quantum manipulation of mechanical resonators. * These authors contributed equally to this work. 1 arXiv:1903.04892v1 [cond-mat.mes-hall]

Mechanical resonators based on a single carbon nanotube are exceptional sensors of mass and force. The force sensitivity in these ultralight resonators is often limited by the noise in the detection of the vibrations. Here, we report on an ultrasensitive scheme based on a RLC resonator and a low-temperature amplifier to detect nanotube vibrations. We also show a new fabrication process of electromechanical nanotube resonators to reduce the separation between the suspended nanotube and the gate electrode down to ∼150 nm. These advances in detection and fabrication allow us to reach displacement sensitivity. Thermal vibrations cooled cryogenically at 300 mK are detected with a signal-to-noise ratio as high as 17 dB. We demonstrate force sensitivity, which is the best force sensitivity achieved thus far with a mechanical resonator. Our work is an important step toward imaging individual nuclear spins and studying the coupling between mechanical vibrations and electrons in different quantum electron transport regimes.

We report on the results obtained from specially designed high electron mobility transistors at 4.2 K: the gate leakage current can be limited lower than 1 aA, and the equivalent input noise-voltage and noise-current at 1 Hz can reach 6.3 nV/Hz1∕2 and 20 aA/Hz1∕2, respectively. These results open the way to realize high performance low-frequency readout electronics under very low-temperature conditions.

We present the noise performance of High Electron Mobility Transistors (HEMT) developed by CNRS/C2N laboratory. Various HEMT's gate geometries with 2 pF to 230 pF input capacitance have been studied at 4 K. A model for both voltage and current noises has been developed with frequency dependence up to 1 MHz. These HEMTs exhibit low dissipation, excellent noise performance and can advantageously replace traditional Si-JFETs for the readout of high impedance thermal sensor and semiconductor ionization cryogenic detectors. Our model predicts that cryogenic germanium detectors of 30 g with 10 eV heat and 20 eV ee baseline resolution are feasible if read out by HEMT-based amplifiers. Such resolution allows for high discrimination between nuclear and electron recoils at low threshold. This capability is of major interest for Coherent Elastic Neutrino Scattering and low-mass dark matter experiments such as Ricochet and EDELWEISS.

With the increasing penetration of wind turbines in the utility grid, new regulation codes have been issued that require them to have low-voltage ride-through capability. In this paper, a passive resistive network consisting of shunt and series elements that are applied at the stator side of a doubly fed induction generation wind turbine is presented. The network is inactive during steady-state operation and enabled for short intervals of time during the initiation of voltage sag and recovery events. Computer simulation and experimental results confirming the validity of this operation during balanced and unbalanced voltage sags are shown in this paper.Index Terms-Doubly fed induction generation (DFIG), lowvoltage ride through, voltage sag, wind turbine.

By implementing dedicated cryogenic circuitry operating in the MHz regime, we have developed a scanning tunneling microscope (STM) capable of conventional, low frequency (<10 kHz), microscopy as well spectroscopy and shot-noise detection at 1 MHz. After calibrating our AC circuit on a gold surface, we illustrate our capability to detect shot-noise at the atomic scale and at low currents (<1 nA) by simultaneously measuring the atomically resolved differential conductance and shot-noise on the high temperature superconductor Bi2Sr2CaCu2O8+x. We further show our direct sensitivity to the temperature of the tunneling electrons at low voltages. Our MHz circuitry opens up the possibility to study charge and correlation effects at the atomic scale in all materials accessible to STM.

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