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Thesis and internships

Thesis :

Topological Transitions in Condensed Matter

 Within a collaboration between LNCMI Grenoble (CNRS) and PHELIQS (CEA) laboratories this PhD project aims at a systematic investigation of the signatures of field induced Fermi surface instabilities (Lifshitz transitions). More precisely, it is planned to measure (thermoelectric) transport properties (Seebeck effect) and thermodynamic properties (magnetization) at low temperatures and under high magnetic field (up to 35T). Comparing these two experimental probes together with theoretical predictions should allow for a clear distinction of the major consequence of Lifshitz transitions : a change in the density of states or extra scattering processes. As a first class of samples, highly correlated electron systems will be investigated (in-house grown high quality single crystals of UCoGe, YbNiSn, etc.) since their generally flat bands at the Fermi level are very sensitive to external magnetic fields.

As a second hot spot it is planned to study recent topological materials like Weyl and Dirac semi-metals (for example Cd3As2 or Na3Bi) which exhibit simpler band structures than the former materials, and are expected to exhibit exotic topological transitions.

This research project has been awarded a special budget by Grenoble University, including a PhD grant of about 1400€ net per month during 3 years ; it will be located in Grenoble, jointly hosted by PHELIQS laboratory and the National High Magnetic Field laboratory.

 Start date : not later than fall 2017

 The PhD student will be jointly supervised by :

 POURRET Alexandre (PI), CEA Grenoble alexandre.pourret@cea.fr

SEYFARTH Gabriel, LNCMI-CNRS  gabriel.seyfarth@lncmi.cnrs.fr

KNEBEL Georg, CEA-Grenoble georg.knebel@cea.fr

 Read the detailed description

 Offer published 18/05/17

 

 

Investigation of strongly correlated electron systems by quantum-oscillation measurements

 

The PhD project is dedicated to quantum-oscillation studies of strongly correlated electron systems in high magnetic fields. Such measurements are the tool-of-choice for the determination of the Fermi-surface topology in metals. In strongly correlated electron systems, high magnetic fields are usually required to observe quantum oscillations. In addition, high magnetic fields often induce electronic phase transitions. Among them are quantum phase transitions, i.e., continues zero temperature phase transitions, around which new quantum phases are expected to emerge. Theoretically, such phase transitions are often accompanied by a Fermi-surface reconstruction. This is one of the key questions that will be addressed experimentally within this PhD project. The student will have a unique opportunity to use state-of-the-art high-field facilities of the European Magnetic Field Laboratory. This includes steady fields to 36 T and beyond available in Grenoble, France and Nijmegen, the Netherlands, as well as pulsed fields beyond to 70 T and higher in Dresden, Germany. All the measurements will be performed at low temperatures. This PhD project is part of a larger French-German collaboration, within which the student will be in contact with theoreticians, who will provide band-structure calculations to be compared with the experiment.

The thesis will be financed by the joint French-German ANR-DFG grant “FermiNESt”. The PhD student will be jointly supervised by Dr. I. Sheikin from LNCMI, CNRS, Grenoble, France (ilya.sheikin@lncmi.cnrs.fr) and Prof. J. Wosnitza from HLD, HZDR, Dresden, Germany (j.wosnitza@hzdr.de).

 Offer published 23/03/2017

 

Internship subjects 2016/2017

Slideshow presentation about LNCMI and activities : PDF document

 Consult below our internship subjects for 2016-2017.

Don’t hesitate to contact directly the person in charge of the subject.

This list is not limitative; do not hesitate to contact stages-g@lncmi.cnrs.fr if a subject that is not present amongst our offers is of interest for your studies!

 

All our internship subjects :

New :

Characterization of high Tc superconductor tapes and coils under high magnetic field and variable temperature

Subject proposed by Xavier Chaud, posted on septembre 30, 2016

Metal-radical compounds: toward systems with high blocking temperature of the magnetization

Subject proposed by Ghenadie Novitchi, posted on october 6, 2016

Multifunctional molecule-based materials: towards multiferroics

Subject proposed by Cyrille Train, posted on october 6, 2016

Nuclear Magnetic Resonance instrumentation and methods for high magnetic fields (36 T) and high frequencies (1.5 GHz)

Subject proposed by Steffen Krämer, posted on october 6, 2016

NMR investigation of the BEC-type quantum spin systems

Subject proposed by Mladen Horvatic, posted on october 10, 2016

Development of a Faraday balance for low temperature and high magnetic field

Subject proposed by Gabriel Seyfarth, posted on october 10, 2016

Field induced phase transitions in quantum materials

Subject proposed by David Le boeuf, posted on october 10, 2016

TURBULENCE MAGNETOHYDRODYNAMIQUE (MHD) EN CONDITIONS EXTRÊMES AU CNRS/LNCMI-GRENOBLE

Subject proposed by François Debray, posted on october 21, 2016

 

 More subjects are expected...