Domaines
Condensed matter
Type of internship
Expérimental Description
The interplay between superconductivity and magnetism has attracted the attention of physicists for years. The coupling between magnetization dynamics and the superconducting state constitutes a pivotal topic, because of its fundamental interest and its relevance in the nascent field of ”superconducting spintronics”.
The spin dynamics can be excited by ferromagnetic resonance (FMR), particularly by shining microwaves that excite the magnetization precession of the macroscopic-magnetic moment. If the ferromagnet is connected to two superconducting electrodes, and these are close enough, this precession of the magnetization expectedly yields the condition for the generation of unconventional superconducting spin-triplets, thus allowing for Josephson coupling across the ferromagnet. The internship is devoted to experimentally verifying this theoretical prediction, and investigating how spin pumping into the superconductor interplays with Josephson coupling. The existing literature on S/F hybrids most often studies (low-Tc) s-wave superconductors. Instead, here we propose (high-Tc) d-wave ones, which are up to now unexplored in this context and display many unique properties. For example, an anisotropic gap results in a high density of QP (Andreev) bound states at the Fermi level.
This internship and the PhD thesis that should follow will focus on understanding the different mechanisms at play, and the potential of these effects for spintronic applications.
Contact
Javier Villegas