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TT: Fachverband Tiefe Temperaturen
TT 22: Focus Session: Frustrated Magnetism and Local Order (joint session MA/TT)
TT 22.4: Talk
Tuesday, March 19, 2024, 11:00–11:15, H 1058
Spatially resolved aging and rejuvenation in a self-induced spin glass — •Lorena Niggli1, Julian H. Strik1, Zhengyuan Liu1, Anders Bergman2, Mikhail I. Katsnelson1, Daniel Wegner1, and Alexander A. Khajetoorians1 — 1Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands — 2Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden
Spin glasses are a puzzling form of magnetic matter lacking long range order and possessing multiple relaxation time scales indicative of aging. These findings are based on ensemble thermodynamic measurements, which leave more to be known about the behaviour of the magnetization locally. Recently, we have discovered that the low temperature magnetic phase of elemental neodymium behaves like a proposed self-induced spin glass relying solely on spin frustration in the absence of disorder for glassiness [1,2]. Here, we explore the aging behaviour of Nd(0001) using spin-polarized scanning tunneling microscopy in varying magnetic fields. We observe a transition from an initial state, reached after cooling into the glass phase, towards a distinct final state, as we perturb the system. Temperature cycling allows us to rejuvenate the system back into its initial state, which hints towards a thermally written memory in this glassy system. Using a new analysis method, we quantify the favourability of the observed local order as well as investigate its link to the energy landscape.
[1] U. Kamber et al., Science 368 (2020).
[2] B. Verlhac et al., Nature Physics 18 (2022).
Keywords: Self-indcued spin glass; Magnetic frustration; Neodymium; Aging; Real space