Calculation of X-ray Magneto-Chiral Dichroism (M/F)

Job Description

Missions

The IMPMC specializes in the calculation of X-ray absorption cross sections and related dichroics, using either mono-electronic DFT approaches in real or reciprocal space, or multi-electronic approaches based on the ligand field model. These calculations allow us to obtain information such as the orientation of molecules deposited on surfaces (X-ray Natural Linear Dichroism or XNLD), the crystal field parameters acting on specific ions, the quadrupole moments of the electronic distribution, the chirality (X-ray Natural Circular Dichroism or XNCD) as well as the orientation of magnetic spin and orbit moments (X-ray Magnetic Circular Dichroism or XMCD).
The researcher in post-doctoral internship will have to calculate the XMChD response of chiral systems experimentally studied within the LUMINESS project. This will require combining all the elements used for XNLD, XNCD and XMCD calculations.
Although our team already has all the fundamental ingredients that we helped to forge, the XMChD response has never been calculated until now; indeed, XMChD signals are at least an order of magnitude smaller than XNCD signals.
In addition to the calculation of the XMChD cross-sections, the post-doctoral researcher must apply the sum rules linking the integral of the XMChD signals to the orbital angular momentum anapole. Although known for some time, these sum rules will be implemented here in a quantitative way and compared to experimental results.

Activity

The researcher will mainly need to: -apply the already existing codes (FDMNES for real space DFT, Quantum Espresso for reciprocal space DFT, QUANTY for ligand field multiplets) to calculate the spectral signatures of XMChD; -apply XMCh sum rules; -write articles about previous calculation activities. The researcher will also have to participate in the XMChD experiments on the ESRF's ID12 line, which is currently the only line to have measured XMChD signals.

Your Profil

Skills

For the scientific part, the researcher is expected to have a solid background in solid-state physics, particularly with regard to magnetism, and knowledge of experimental measurements on synchrotron radiation, shows a strong desire to simulate experimental results. Prior experience in this area is not necessarily expected, but it will require a strong appetite to learn. Knowledge of spoken and written English is essential. A strong scientific autonomy is also expected. Since the post-doctoral internship project is integrated into the LUMINESS project of the PEPR LUMA, the researcher is expected to have strong interpersonal skills and strong teamwork skills.

Your Work Environment

Most of the work will take place at the IMPMC (Paris 5e). There could also be one or two weeks of work in Grenoble on the ID12 line of the ESRF for the collection of XMChD measurements. The researcher will be integrated into the MIMABADI team (mineralogy and magnetism of low dimensionality) of the IMPMC with also a strong connection with the TQM team (quantum theory of materials). The IMPMC people involved in this project are: Ph. Sainctvait, A. Juhin, M.-A. Arrio, Ch. Brouder.

Constraints and risks

Scientific risks: A large part of the theoretical data has already been acquired. The simulation codes are available to the IMPMC teams. Therefore, there are no major scientific risks associated with this research. On the other hand, the quality of the results will depend heavily on the involvement of the researcher to obtain the best simulations and to extract solid scientific information. The IMPMC has computer equipment to test the calculations. For the largest calculations, we use the MESU mesocenter or the IDRIS machines. There is no proven risk of running out of computing power. For synchrotron radiation experiments, the IMPMC team generally has more than 10 weeks of synchrotron beam buffers per year and the risk of not being able to measure the necessary XMChD signals is very low. Risks at work: Simulations in the IMPMC: Since work is mainly a calculation task, no physical risk is detected for this activity. Synchrotron experiments: the risks are covered by the "security training test" prior to access to the ESRF site.

Compensation and benefits

Compensation

3000

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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