학술논문
Real-time observation of non-equilibrium phonon-electron energy and angular momentum flow in laser-heated nickel.
Document Type
Article
Author
Shokeen, Vishal; Heber, Michael; Kutnyakhov, Dmytro; Xiaocui Wang; Yaroslavtsev, Alexander; Maldonado, Pablo; Berritta, Marco; Wind, Nils; Wenthaus, Lukas; Pressacco, Federico; Chul-Hee Min; Nissen, Matz; Mahatha, Sanjoy K.; Dziarzhytski, Siarhei; Oppeneer, Peter M.; Rossnagel, Kai; Elmers, Hans-Joachim; Schönhense, Gerd; Dürr, Hermann A.
Source
Subject
*ANGULAR momentum (Mechanics)
*ELECTRON spin
*PICOSECOND pulses
*PHOTOELECTRON spectroscopy
*DEGREES of freedom
*MOMENTUM transfer
*MAGNETIC declination
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Language
ISSN
2375-2548
Abstract
Identifying the microscopic nature of non-equilibrium energy transfer mechanisms among electronic, spin, and lattice degrees of freedom is central to understanding ultrafast phenomena such as manipulating magnetism on the femtosecond timescale. Here, we use time-and angle-resolved photoemission spectroscopy to go beyond the often-used ensemble-averaged view of non-equilibrium dynamics in terms of quasiparticle temperature evolutions. We show for ferromagnetic Ni that the non-equilibrium electron and spin dynamics display pronounced variations with electron momentum, whereas the magnetic exchange interaction remains isotropic. This highlights the influence of lattice-mediated scattering processes and opens a pathway toward unraveling the still elusive microscopic mechanism of spin-lattice angular momentum transfer. [ABSTRACT FROM AUTHOR]