# Quantum tunnelling of the magnetisation in single-molecule magnet isotopologue dimers

Moreno-Pineda, Eufemio; Taran, Gheorghe; Wernsdorfer, Wolfgang; Ruben, Mario

##### Abstract:
Quantum tunnelling of the magnetisation plays a major role in the magnetic properties of lanthanide Single-Molecule Magnets: while it is considered a problem for data storage device applications since it leads to information loss, it is an essential pre-requisite for the read-out and manipulation of the nuclear states in Quantum Information Processing schemes. Here we describe two isotopologue dysprosium dimers, i.e. [($^{163}$Dy(tmhd)$_{3}$)$_{2}$(bpym)] and [($^{164}$Dy(tmhd)$_{3}$)$_{2}$(bpym)] (tmd = tris(tetramethylheptanedionato) and bpym = bipyrimidine), where the nuclear spin presence or absence clearly affects the magnetic properties of the systems. Through μ-SQUID studies at milli-Kelvin temperatures and alternating current magnetic measurements, we find significant differences in the magnetic behaviour of both complexes. While simulation of the hysteresis loops at 30 mK reveals that the presence of nuclear spin does not influence the tunnelling rate, we find that it facilitates the coupling to the phonon bath enhancing the direct relaxation process; an observation reflected in the temperature and field dependence of the relaxation rates.

 Zugehörige Institution(en) am KIT Physikalisches Institut (PHI)Institut für Nanotechnologie (INT) Publikationstyp Zeitschriftenaufsatz Publikationsjahr 2019 Sprache Englisch Identifikator ISSN: 2041-6520, 2041-6539 KITopen-ID: 1000095695 HGF-Programm 43.21.04 (POF III, LK 01)Molecular Engineering Erschienen in Chemical science Band 10 Heft 19 Seiten 5138-5145 Nachgewiesen in Web of ScienceScopus
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