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Magnetic Metamaterials and selective electronic erotion in complex oxides

Date: 2023-12-13
Time: 09:30
Venue: MA505
Speaker: Prof. Alejandro V. Silhanek

University of Liège





In this talk I will present our recent result on two different research lines. In the first part we will address magnetic metamaterials which have demonstrated promising perspectives to improve the efficiency of magnetic flux concentrators. In this talk, I'll focus on the effects of downscaling these devices for on-chip integration, the influence of the non-linear magnetic response of the ferromagnetic components, their magnetic irreversibility, the formation of magnetic domains, as well as the effects of geometry and size of the devices. The results demonstrate that the implementation of metasurfaces at the microscale opens up new technological possibilities for enhancing the performance of magnetic field detectors and remotely charging small electric devices, thus paving the way toward new approaches in information and communication technologies. In the second part of the talk, we focus on the oxygen doping through current-stimulated oxygen migration in YBa2Cu3O7?δ superconducting bridges. The resulting propagating front of current-dependent doping δ is probed in situ by optical microscopy and scanning electron microscopy. Additional photo-induced conductivity and Raman scattering investigations, reveal an inhomogeneous oxygen vacancy distribution with a controllable propagation speed permitting us to estimate the oxygen diffusivity. These findings provide direct evidence that the microscopic mechanism at play in electrical doping of cuprates involves diffusion of oxygen atoms with the applied current.


Alejandro Silhanek is a professor of Department of Physics, Faculty of Sciences at the University of Liège, Belgium. He holds a master degree in physics from the University of La Plata, Argentina, and a Ph.D. degree in Physics obtained from Instituto Balseiro, Bariloche (Argentina) in 2001. He was awarded Directors funded Postdoctoral fellow, Los Alamos National Laboratory (USA) from 2004 to 2006 and Postdoctoral Researcher FWO (Belgium) from 2006 to 2011. The scientific activities of his group are mainly within the field of experimental mesoscopic physics, nanoscience and nanotechnology, magnetism, superconductivity, and quantum transport.

邀 请 人:李 潜

联 系 人:王慧颖