Who: Julen Ibaņez-Azpiroz (CFM)
Place: CFM Auditorium
Date: Friday, 20 October 2017, 12:00
Single-adatoms deposited on metallic substrates offer an exceptional playground for studying magnetism at the atomic scale and give rise to many intriguing questions. For instance, although several adatoms exhibit a large magnetic anisotropy energy as measured by X-ray Magnetic Circular Dichroism , the very same adatoms behave as paramagnetic objects when probed by Scanning Tunneling Spectroscopy (STS) [2, 3]. Motivated by this apparent contradiction, we analyze the role of quantum fluctuations of the adatom?s spin at T=0, the so-called zero-point spin-fluctuations utilizing time-dependent density functional theory . Remarkably, while spin-fluctuations weaken magnetism, they can be used to detect magnetic signals even in non-magnetic adatoms, which can exhibit intense paramagnetic spin-excitations tunable with a magnetic field and potentially observable with inelastic STS .
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