Berlin 2024 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 35: Superconducting Electronics: SQUIDs, Circuit QED
TT 35.1: Vortrag
Mittwoch, 20. März 2024, 09:30–09:45, H 2053
Spin Hamiltonian of 3d/4f single molecule magnets revealed by micro-SQUID-EPR — •Sagar Paul1, Mario Ruben2, Shouvik Chattopadhyay3, Eufemio Moreno-Pineda4, and Wolfgang Wernsdorfer1 — 1Physikalisches Institut, Karlsruhe Institute of Technology (KIT), Germany. — 2Institute of Nanotechnology, Karlsruhe Institute of Technology, Germany. — 3Jadavpur University, Kolkata - 700032, India. — 4Universidad de Panamá, 0824, Panamá.
The single molecule magnets (SMM) exhibit magnetic anisotropy at molecular level, slow relaxation and resonant quantum tunneling of magnetization (QTM) leading to numerous applications in molecular spintronics and quantum information processing. The hyperfine levels observed in micro-SQUID M(H) measurements open possibilities of utilizing nuclear spin in quantum computation. Further, recent observations of large decoherence times of electronic spin states in diluted single crystals of Gd SMMs [1], has re-encouraged the research on such SMMs. A combined micro-SQUID-EPR [2] stands as a unique experimental technique to precisely study the magnetism, in situ while exciting a single crystal with microwave pulse. With this technique, the M(H) loops of 3d/4f monomer/dimer SMMs studied in 30 mK - 5 K range, and for different frequencies of microwave excitation, exhibit absorption peaks associated to specific spin transitions. The peak positions plotted with RF frequency (1-40 GHz) and field angles reveal the entire spin Hamiltonian of the system [2].
[1] G. Handzlik et al., J. Phys. Chem. Lett. 11 (2020) 1508
[2] G. Taran et al., Nat. Commun. 14 (2023) 3361
Keywords: micro-SQUID; Single Molecule Magnets; Qubit; Magnetism; Quantum Tunneling