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Departamento de Física promove colóquios especiais nesta semana
Os eventos acontecerão amanhã (21) e sexta (22)
O Departamento de Física da UFPE realizará amanhã (21) e sexta-feira (22) dois colóquios. A palestra “Spin-Orbit Technologies: From Magnetic Memory to Terahertz Generation” será ministrada amanhã por Hyunsoo Yang, do Department of Electrical and Computer Engineering, National University of Singapore, às 16h.
Já o colóquio da sexta, de título “Hyperspectral Imaging and Microscopy”, será apresentado por Cristian Manzoni, do Istituto di Fotonica e Nanotecnologie – CNR - Dipartimento di Fisica, Politecnico di Milano também às 16h. As duas atividades ocorrerão no auditório do DF.
Spintronic devices utilize an electric current to alter the state of a magnetic material and thus find great applications in magnetic memory. Over the last decade, spintronic research has focused largely on techniques based on spin-orbit coupling, such as spin-orbit torques (SOTs), to alter the magnetic state. The phenomenon of spin-orbit coupling in magnetic heterostructures was also recently used to generate terahertz emission and thus bridge the gap between spintronics and optoelectronics research. I will introduce the basic concepts of SOTs, such as their physical origin, the effect of SOTs on a magnetic material, and how to quantitatively measure this effect. Next, I will discuss the latest trends in SOT research, such as the exploration of novel material systems like topological insulators and two-dimensional materials to improve the operation efficiency. Following this, some of the technical challenges in SOT-based magnetic memory will be highlighted. Moving forward, I will introduce the process of terahertz generation in magnetic heterostructures , where the spin-orbit coupling phenomenon plays a dominant role. I will discuss the details of how this terahertz emission process can be extended to novel material systems such as ferrimagnets, topological materials, and 2D materials. The final section will focus on how the terahertz generation process can be used to measure SOTs in magnetic heterostructures, thus highlighting the interrelation between terahertz generation and the SOTs, which are linked by the underlying spin-orbit coupling.
Spectral imaging, also known as imaging spectroscopy, refers to methods and devices for acquiring a complete light spectrum for each point in the image of a scene. It provides much richer information with respect to standard imaging, enabling to identify materials or detect dynamical processes. Spectral imaging has been applied to a wide range of scientific investigations, such as remote sensing, pigment determination in biology, medicine, coastal ocean imaging, water analysis, agriculture, cultural heritage and archaeology, just to cite a few. In particular, hyperspectral imaging aims at acquiring the whole continuous spectrum of each point of the scene. A powerful approach to this aim is to combine classical imaging with Fourier-transform spectrometry. In this talk, I will describe the main properties of the spectral imaging and the current acquisition approaches. I will also show the most recent advancements obtained at the Istituto di Fotonica e Nanotecnologie (IFN-CNR), based on an innovative optical device. Our compact hyperspectral system is able to acquire spectral reflectance and fluorescence images with high sensitivity, broad spectral coverage and high spectral resolution. Examples of hyperspectral remote-sensing and microscopy images will be provided and discussed.
Departamento de Física