Sophie Charpentier
Chalmers University of Technology
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Sophie Charpentier.
Nano Letters | 2015
André Dankert; Johannes Geurs; M. Venkata Kamalakar; Sophie Charpentier; Saroj Prasad Dash
Topological insulators (TIs) are a new class of quantum materials that exhibit a current-induced spin polarization due to spin-momentum locking of massless Dirac Fermions in their surface states. This helical spin polarization in three-dimensional (3D) TIs has been observed using photoemission spectroscopy up to room temperatures. Recently, spin polarized surface currents in 3D TIs were detected electrically by potentiometric measurements using ferromagnetic detector contacts. However, these electric measurements are so far limited to cryogenic temperatures. Here we report the room temperature electrical detection of the spin polarization on the surface of Bi2Se3 by employing spin sensitive ferromagnetic tunnel contacts. The current-induced spin polarization on the Bi2Se3 surface is probed by measuring the magnetoresistance while switching the magnetization direction of the ferromagnetic detector. A spin resistance of up to 70 mΩ is measured at room temperature, which increases linearly with current bias, reverses sign with current direction, and decreases with higher TI thickness. The magnitude of the spin signal, its sign, and control experiments, using different measurement geometries and interface conditions, rule out other known physical effects. These findings provide further information about the electrical detection of current-induced spin polarizations in 3D TIs at ambient temperatures and could lead to innovative spin-based technologies.
Nano Letters | 2013
Tom Yager; Arseniy Lartsev; Sumedh Mahashabde; Sophie Charpentier; Dejan Davidovikj; Andrey Danilov; Rositza Yakimova; Vishal Panchal; Olga Kazakova; Alexander Tzalenchuk; Samuel Lara-Avila; Sergey Kubatkin
We show that inspection with an optical microscope allows surprisingly simple and accurate identification of single and multilayer graphene domains in epitaxial graphene on silicon carbide (SiC/G) and is informative about nanoscopic details of the SiC topography, making it ideal for rapid and noninvasive quality control of as-grown SiC/G. As an illustration of the power of the method, we apply it to demonstrate the correlations between graphene morphology and its electronic properties by quantum magneto-transport.
Physical Review B | 2014
Luca Galletti; Sophie Charpentier; M. Iavarone; P. Lucignano; D. Massarotti; Riccardo Arpaia; Yusuke Suzuki; Kazuo Kadowaki; Thilo Bauch; A. Tagliacozzo; F. Tafuri; Floriana Lombardi
In superconductor-topological insulator-superconductor hybrid junctions, the barrier edge states are expected to be protected against backscattering, to generate unconventional proximity effects, and, possibly, to signal the presence of Majorana fermions. The standards of proximity modes for these types of structures have to be settled for a neat identification of possible new entities. Through a systematic and complete set of measurements of the Josephson properties we find evidence of ballistic transport in coplanar Al-Bi2Se3-Al junctions that we attribute to a coherent transport through the topological edge state. The shunting effect of the bulk only influences the normal transport. This behavior, which can be considered to some extent universal, is fairly independent of the specific features of superconducting electrodes. A comparative study of Shubnikov-de Haas oscillations and scanning tunneling spectroscopy gave an experimental signature compatible with a two-dimensional electron transport channel with a Dirac dispersion relation. A reduction of the size of the Bi2Se3 flakes to the nanoscale is an unavoidable step to drive Josephson junctions in the proper regime to detect possible distinctive features of Majorana fermions.
Applied Physics Letters | 2014
Riccardo Arpaia; Marco Arzeo; Shahid Nawaz; Sophie Charpentier; Floriana Lombardi; Thilo Bauch
We present results on ultra low noise YBa
Applied Physics Express | 2014
Attila Fülöp; Yuxin Song; Sophie Charpentier; Peixiong Shi; Maria Ekström; Luca Galletti; Riccardo Arpaia; Thilo Bauch; Floriana Lombardi; Shumin Wang
_2
Physical Review B | 2016
D. Massarotti; B. Jouault; V. Rouco; Sophie Charpentier; Thilo Bauch; A. Michon; A. de Candia; P. Lucignano; Floriana Lombardi; Francesco Tafuri; A. Tagliacozzo
Cu
IEEE Transactions on Applied Superconductivity | 2017
Luca Galletti; Sophie Charpentier; Yuxin Song; Dmitry Golubev; Shu M. Wang; Thilo Bauch; Floriana Lombardi
_3
Physical Review B | 2018
André Dankert; Priyamvada Bhaskar; Dmitrii Khokhriakov; Isabel Harrysson Rodrigues; Bogdan Karpiak; Venkata Kamalakar Mutta; Sophie Charpentier; Ion Garate; Saroj Prasad Dash
O
Scientific Reports | 2017
Maciej Wiesner; A. Trzaskowska; B. Mroz; Sophie Charpentier; Supen Wang; Yuxin Song; Floriana Lombardi; P. Lucignano; G. Benedek; Davide Campi; Marco Bernasconi; F. Guinea; A. Tagliacozzo
_{7-\delta}
arXiv: Superconductivity | 2014
Riccardo Arpaia; Marco Arzeo; Shahid Nawaz; Sophie Charpentier; Floriana Lombardi; Thilo Bauch
nano Superconducting QUantum Interference Devices (nanoSQUIDs). To realize such devices, we implemented high quality YBCO nanowires, working as weak links between two electrodes. We observe critical current modulation as a function of an externally applied magnetic field in the full temperature range below the transition temperature