Other postdoc positions available<\/strong>: contact Benjamin Piot ( benjamin.piot [at ] lncmi.cnrs.fr )<\/p>\n [\/et_pb_text][et_pb_image src=”https:\/\/lncmi.cnrs.fr\/wp-content\/uploads\/2025\/02\/UNADJUSTEDNONRAW_thumb_6493.jpg” title_text=”UNADJUSTEDNONRAW_thumb_6493″ _builder_version=”4.27.4″ _module_preset=”default” width=”66%” module_alignment=”center” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ admin_label=”Annuaire” module_id=”personnel” _builder_version=”4.27.0″ _module_preset=”default” global_colors_info=”{}”][et_pb_row _builder_version=”4.25.2″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.25.2″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n [\/et_pb_text][et_pb_code _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”] [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_4,3_4″ _builder_version=”4.27.4″ _module_preset=”default” module_alignment=”center” global_colors_info=”{}”][et_pb_column type=”1_4″ _builder_version=”4.25.2″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/lncmi.cnrs.fr\/wp-content\/uploads\/2025\/02\/RDNMR-FQH-GaAs.png” title_text=”RDNMR FQH GaAs” _builder_version=”4.27.4″ _module_preset=”default” width=”300px” width_tablet=”150%” width_phone=”150%” width_last_edited=”on|tablet” height=”300px” height_tablet=”150px” height_phone=”150px” height_last_edited=”on|desktop” global_colors_info=”{}” max_width__hover_enabled=”off|desktop” max_height__hover_enabled=”off|desktop”][\/et_pb_image][\/et_pb_column][et_pb_column type=”3_4″ _builder_version=”4.25.2″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” min_height=”362.2px” custom_padding=”||0px|||” global_colors_info=”{}”]<\/p>\n We have been working on the physics of the filling factor nu= 5\/2 fractional quantum Hall effect. The wave function which is supposed to describe this state theoretically, the so-called Moore-Read state, bears unique \u201cnon-abelian anyonic\u201d quantum statistics which would underly a new paradigm for topological (fault tolerant) quantum computation. However, a verification of another key property of the Moore-Read state, which is the p-wave symmetry of the electron wave function at nu= 5\/2, had so far been missing. Using Resistively Detected Nuclear Magnetic Resonance (RDNMR) at very low temperature, we have unravelled the sought-after spin polarization of this state and shown that, in agreement with the Moore-Read theory, electron are fully spin polarized in the nu= 5\/2 fractional quantum Hall state. This results is a necessary condition for the validity of the Moore-Read theory, and interferometric experiments will now have to determine the exact nature of quantum statistics in the nu= 5\/2 state. Nowadays, bilayer graphene has emerged as a new platform to study such statistics and a new project is being launched in 2025 for similar studies<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.27.4″ _module_preset=”default” custom_padding=”18px|||||” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” custom_margin=”||4px|||” global_colors_info=”{}”]<\/p>\n Thanks to a newly developed phase-sensitive resistive detection technique of spin resonance, we can perform microwave absorption studies in a large frequency\/magnetic field\/temperature phase space (see techniques below). Such experiments enable us to determine the low-energy magnon excitations spectrum of various van der Waals magnets. The example of <\/span>CrSBr<\/span> \u00a0is given in the figure below<\/span><\/p>\n [\/et_pb_text][et_pb_image src=”https:\/\/lncmi.cnrs.fr\/wp-content\/uploads\/2025\/02\/crsbr-piot.png” title_text=”crsbr-piot” align=”center” _builder_version=”4.27.4″ _module_preset=”default” max_width=”87%” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” text_orientation=”center” custom_margin=”-24px|||||” global_colors_info=”{}”]<\/p>\n Magnetic-field dependence of two low-energy magnon modes in CrSBr measured in an applied field parallel to the three principal crystallographic directions. [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_accordion _builder_version=”4.27.4″ _module_preset=”default” hover_enabled=”0″ global_colors_info=”{}” sticky_enabled=”0″][et_pb_accordion_item open=”on” _builder_version=”4.27.4″ _module_preset=”default” hover_enabled=”0″ global_colors_info=”{}” sticky_enabled=”0″]<\/p>\n Electrons in 2D silicon-based system possess a \u201cvalley\u201d degree of freedom, just like in the more recently discovered 2D systems like graphene or transition metal dichalcogenides. This twofold degeneracy is often experienced as a source of complication for quantum computation perspectives in silicon \u201cQ-bits\u201d systems, but was also more recently put forward as an asset for potential \u201cvalleytronics\u201d applications, where the valley degree of freedom of quantum states can be controlled and operated, the same ways as spins in \u201cspintronics\u201d. The single-particle valley splitting is far from being fully understood. Indeed, the possibility of tuning the valley polarisation of 2D electrons in silicon is actually very much dependent on the whole device\u2019s structure and nature. For example, the valley splitting at the Si\/SiO<\/em>2 usual MOSFETs (Metal-Oxide-Field-Effect-Transistor) interface, where SiO<\/em>2 is a thermal oxide, can be of the order of a few meV. In Si\/SiGe <\/em>heterojunctions, it is reduced down to the order of 10-100 \u00b5eV <\/em>. Motivated by understanding interface-dependent valley splittings in 2D silicon, we investigate valley polarization in doubly gated Silicon MOSFETS involving yet another interface: the one between silicon and a \u201chigh-k” dielectric which is ubiquitous in modern silicon commercial MOSFETs.<\/p>\n Some results of our investigations have just been published:<\/p>\n “Wide Electrical Tunability of the Valley Splitting in a Doubly Gated Silicon-on-Insulator Quantum Well” ,\u00a0 <\/strong>Nano Lett. 2025, 25, 36, 13557\u201313562.<\/a><\/p>\n [\/et_pb_accordion_item][\/et_pb_accordion][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”2_3,1_3″ _builder_version=”4.27.4″ _module_preset=”default” module_alignment=”center” custom_padding=”0px||0px|||” global_colors_info=”{}”][et_pb_column type=”2_3″ _builder_version=”4.25.2″ _module_preset=”default” global_colors_info=”{}”][et_pb_accordion _builder_version=”4.27.4″ _module_preset=”default” module_alignment=”center” height=”168px” custom_margin=”27px||||false|false” global_colors_info=”{}”][et_pb_accordion_item title=”mK specific heat of 2D systems” open=”on” _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n We are developing novel thermodynamic tools for the experimental study two-dimensional electron systems in the quantum Hall regime. This project is performed in collaboration with C2N (Orsay) and Neel institute (Grenoble), and involves high-mobility suspended 2DEG with embedded sensitive thermometry.<\/span><\/p>\n [\/et_pb_accordion_item][\/et_pb_accordion][\/et_pb_column][et_pb_column type=”1_3″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/lncmi.cnrs.fr\/wp-content\/uploads\/2025\/02\/mKcp.jpg” title_text=”mKcp” _builder_version=”4.27.4″ _module_preset=”default” width_tablet=”150%” width_phone=”150%” width_last_edited=”on|tablet” height=”246px” height_tablet=”150px” height_phone=”150px” height_last_edited=”on|desktop” global_colors_info=”{}” max_width__hover_enabled=”off|desktop” max_height__hover_enabled=”off|desktop”][\/et_pb_image][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ module_id=”techniques” _builder_version=”4.27.0″ _module_preset=”default” locked=”off” global_colors_info=”{}”][et_pb_row _builder_version=”4.26.0″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.26.0″ _module_preset=”default” global_colors_info=”{}”][et_pb_text module_id=”techniques” _builder_version=”4.27.0″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.27.2″ _module_preset=”default” locked=”off” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.2″ _module_preset=”default” global_colors_info=”{}”][et_pb_toggle title=”High B \/ low T transport on nano devices” _builder_version=”4.27.4″ _module_preset=”default” text_orientation=”left” locked=”off” global_colors_info=”{}”]<\/p>\n [\/et_pb_toggle][et_pb_toggle title=”Resistively-detected microwave absorptions” _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n Reference: C. W. Cho, A. Pawbake, N. Aubergier, A. L. Barra, K. Mosina, Z. Sofer, M. E. Zhitomirsky, C. Faugeras, and B. A. Piot, Microscopic parameters of the van der waals crsbr antiferromagnet from microwave absorption experiments, Phys. Rev. B 107, 094403 (2023).<\/a><\/li>\n<\/ul>\n [\/et_pb_toggle][et_pb_toggle title=”Resistively-detected NMR in low dimensional systems” _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n We have a long tradition in developing resistively-detected NMR techniques, see for example: <\/span>M. Stern, B. A. Piot, et al<\/em>, Phys. Rev. Lett. 108<\/strong>, 066810 (2012)<\/a> and B. A. Piot et al,<\/em>\u00a0 Phys. Rev. Lett. 116<\/strong>, 106801 (2016)<\/a>.<\/p>\n [\/et_pb_toggle][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_sidebar _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_sidebar][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ admin_label=”Publications” module_id=”publications” _builder_version=”4.27.0″ _module_preset=”default” global_colors_info=”{}”][et_pb_row column_structure=”1_2,1_2″ _builder_version=”4.25.2″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”1_2″ _builder_version=”4.25.2″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.25.2″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n [\/et_pb_text][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_accordion _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_accordion_item title=”LDS Group referred publications (2012- Sept 2025)” open=”on” _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\nResearch staff<\/h3>\n
![\"PIOT](\"https:\/\/lncmi.cnrs.fr\/wp-content\/uploads\/2025\/05\/Benjamin_PIOT.jpg\")
<\/a><\/figure><\/div>PIOT Benjamin<\/a><\/span><\/h3>
Research topics<\/h3>\n
New quantum statistics in the quantum Hall regime<\/h3>\n
M. Stern, B. A. Piot et al, \u201cNMR Probing of the Spin Polarization of the \u03bd = 5\/2 Quantum Hall State\u201d Phys. Rev. Lett. 108, 066810 (2012).<\/p>\nMagnons in van der Waals magnets<\/strong><\/h3>\n
Such spectra reveal anisotropies, magnetic transitions, and a strong magnon-magnon coupling in this material.<\/em><\/p>\nValley degeneracy in silicon<\/h3>\n
Techniques<\/h2>\n
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Microwave absorption can be studied in a large continuous frequency range (f=1-220 GHz) for temperatures between 1.3 K and 60 K, and under magnetic fields up to 16 T (30 T under development).<\/span><\/p>\nPublications<\/h3>\n
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