Domain, Specialties : Condensed matter physics
Keywords: magnetic excitations, disorder
Research Unit : LLB / NFMQ
Summary
The search of magnetoelectric multiferroic materials, where magnetic order and ferroelectricity are coupled to each other is an issue of keen interest in condensed matter physics and in spin-related emerging communication technologies [1-2]. However, the low-magnetic ordering temperatures in such materials, typically below 100 K, critically restrict their potential use for spintronics and low-power magnetoelectric devices. YBaCuFeO5, however, stands out as an exception, and is among the most promising examples of magnetism-driven ferroelectricity, with a spiral magnetic order stabilized at quite high temperature (200K). The mechanism behind this remarkable property, called “spiral order by disorder”, involves the intrinsic Cu/Fe disorder observed in this material [3]. Strikingly, the Fe-O-Fe exchange is strongly antiferromagnetic (AFM) J ~ 98 meV, while the Fe-O-Cu one is ferromagnetic and 1 to 2 orders of magnitude weaker.
Given this scientific context, the aim of this internship is to develop a Monte-Carlo code to calculate the spin dynamics in such a disordered system. This code will serve as a useful tool for predicting and analyzing future inelastic neutron scattering experiments planned at the high flux research reactor (ILL, Grenoble).
[1] T. Goto et al. Phys. Rev. Lett. 92, 257201 (2004).
[2] S.-W. Cheong and M. Mostovoy, Nat. Mater. 6, 13 (2007).
[3] A. Scaramucci et al. Phys. Rev. X 8 011005 (2018).
Full description
The search of magnetoelectric multiferroic materials, where magnetic order and ferroelectricity are coupled to each other is an issue of keen interest in condensed matter physics and in spin-related emerging communication technologies [1-2]. However, the low-magnetic ordering temperatures in such materials, typically below 100 K, critically restrict their potential use for spintronics and low-power magnetoelectric devices. YBaCuFeO5, however, stands out as an exception, and is among the most promising examples of magnetism-driven ferroelectricity, with a spiral magnetic order stabilized at quite high temperature (200K). The mechanism behind this remarkable property, called “spiral order by disorder”, involves the intrinsic Cu/Fe disorder observed in this material [3]. Strikingly, the Fe-O-Fe exchange is strongly AFM J ~ 98 meV while the Fe-O-Cu one is ferromagnetic and 1 to 2 orders of magnitude weaker.
Given this scientific context, the aim of this internship is to develop a Monte-Carlo code to calculate the spin dynamics in such a disordered system. This code will serve as a useful tool for predicting and analyzing future inelastic neutron scattering experiments planned at the high flux research reactor (ILL, Grenoble).
[1] T. Goto et al. Phys. Rev. Lett. 92, 257201 (2004).
[2] S.-W. Cheong and M. Mostovoy, Nat. Mater. 6, 13 (2007).
[3] A. Scaramucci et al. Phys. Rev. X 8 011005 (2018).
Location
Ile-de-France
Saclay
Internship conditions
- Internship duration: 4 months
- Level of study: Bac+5
- Training: Master 2
- Continuation in PhD thesis: Yes
- Application deadline: 9 septembre 2024
Experimental skills
Useful methods and technics:
Monte Carlo, Neutron scattering
Computer languages and software:
Fortran 90, C
Langue : Anglais
Links
- Web page of the laboratory LLB/NFMQ
- Personal Web page S. Petit
Supervisor
Tuteur
SYLVAIN PETIT
Phone: 01 69 08 12 34
Email :
Head of the laboratory LLB / NFMQ
Françoise DAMAY