Ultrafast Xuv Magnetic Circular Dichroism: Observing Spin Transport At Interfaces

Baker, Robert

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https://hdl.handle.net/2142/116955 Copy

Description

Title

Ultrafast Xuv Magnetic Circular Dichroism: Observing Spin Transport At Interfaces

Author(s)

Baker, Robert

Contributor(s)

• Londo, Stephen
• Hruska, Emily B.
• Bandaranayake, Savini Sandunika
• Gajapathy, Harshad
• Schultze, Martin

Issue Date

2022-06-21

Keyword(s)

Mini-symposium: Spectroscopy meets Chemical Dynamics

Abstract

In time resolved spectroscopy of molecular systems, spectral signatures are directly correlated with processes such as charge migration, intra and intermolecular vibrational relaxation, internal conversion, and intersystem crossing. However, the challenge of probing these analogous processes in material systems with surface sensitivity and ultrafast time resolution motivates the goal to extend a molecular-level understanding to dynamics at surfaces and interfaces. In this talk, we describe the recent ability to directly observe spin-polarized electron transport at semiconductor surfaces using XUV Magnetic Circular Dichroism (XUV-MCD) in a reflection geometry. The ability to produce spin polarized currents at interfaces underlies many promising applications ranging from spintronics to enantioselective photocatalysis, but designing materials capable of these applications requires an improved understanding of spin-dependent electron dynamics at interfaces. Towards this goal, XUV-MCD reflection-absorption spectroscopy provides direct observation of spin dynamics in magnetic materials with ultrafast time resolution and surface sensitivity. Yttrium iron garnet (Y$_{3}$Fe$_{5}$O$_{12}$, YiG) is a ferrimagnetic semiconductor, consisting of two sub-lattices based on octahedrally and tetrahedrally coordinated Fe(III) centers. A combination of linearly and circularly polarized XUV measurements at the Fe M$_{2,3}$-edge of YiG provides a detailed picture of these lattice-dependent electron dynamics, which give rise to spin polarized current at the YiG surface upon band gap excitation. These findings have important applications towards the development of spin selective photocatalysts as well as new platforms for light-induced control of ultrafast spin polarization at material interfaces.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Handle URL

https://hdl.handle.net/2142/116955

DOI

https://doi.org/10.15278/isms.2022.TA02

Copyright and License Information

Copyright 2022 held by the authors

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