Dr. Ricardo Zarzuela

Spintronics offers new routes towards the design of energy-efficient architectures for the next generation of high-speed electronic devices. However, it also faces the problem of fast degradation of spin signals due to decoherence processes. Topological protection of spin textures seems to play a fundamental role in overcoming this issue and leads to long relaxation lengths. It is worth remarking that this topological robustness usually relies on the existence of an underlying rotational symmetry in spin space, which breaks down in the presence of parasitic (relativistic) interactions, the latter naturally arising during the fabrication process of spintronic devices.

Three dimensional skyrmion diffusion.

Magnetic systems with frustrated interactions dominated by exchange, referred to as frustrated magnets hereafter, are particularly interesting in this regard, since these symmetry-breaking interactions become ‘averaged-out’ at the macroscopic level and the topological robustness is effectively restored [1]. Furthermore, frustrated magnets, described by a noncollinear order parameter, host a rich variety of magnetic solitons (e.g., Shankar skyrmions and hedgehogs) which are attractive from a technological point of view due to their potential usage as building blocks for information and energy storage.

My research focus on exploring transport phenomena in frustrated magnets. More specifically, I am interested in the properties of the effective spin superfluid phase and the hydrodynamics of topological solitons emerging in the insulating scenario, along with the (spin) transport of charge carriers in magnetic conductors with frustrated interactions. Finally, I am also interested in the dynamical properties of skyrmions and other solitons in conventional (anti)ferromagnets, with special attention to those arising in the quantum regime.


Publications (Highlights):

[1] R. Zarzuela, V.K. Bharadwaj, K.-W. Kim, J. Sinova and K. Everschor-Sitte, “ Stability and dynamics of in-plane skyrmions in collinear ferromagnets”. Phys. Rev. B 101, 054405 (2020).

[2] H. Ochoa, R. Zarzuela and Y. Tserkovnyak, “Spin hydrodynamics in amorphous magnets”. Phys. Rev. B 98, 054424 (2018).

[3] R. Zarzuela, H. Ochoa and Y. Tserkovnyak, “Hydrodynamics of three-dimensional skyrmions in frustrated magnets”. arXiv:1901.01208 (2019).

[4] S.K. Kim, H. Ochoa, R. Zarzuela and Y. Tserkovnyak, “Realization of the Haldane-Kane-Mele model in a system of localized spins”. Phys. Rev. Lett. 117, 227201 (2016).