Anisotropy of the molecular magnet V$_{15}$ spin Hamiltonian detected by high-field electron spin resonance

M. Martens (1) , J. van Tol (2) , N. S. Dalal (3) , S. Bertaina (4) , B. Barbara (5) , B. Tsukerblat (6) , A. Müller (7) , S. Garai (7) , S. Miyashita (8) , I. Chiorescu (1)

1 FSU - Florida State University [Tallahassee]
2 NHMFL - National High Magnetic Field Laboratory
3 DCB - Department of Chemistry and Biochemistry, Tallahassee
4 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
5 NEEL - QuantECA - Circuits électroniques quantiques Alpes
6 Department of Chemistry
7 Fakultät für Chemie [Universität Bielefeld]
8 Department of Physics

The molecular compound K$_6$[V$^{IV}_{15}$As$^{III}_6$O$_{42}$(H$_2$O)] $\cdot$ 8H$_2$O, in short V$_{15}$, has shown important quantum effects such as coherent spin oscillations. The details of the spin quantum dynamics depend on the exact form of the spin Hamiltonian. In this study, we present a precise analysis of the intramolecular interactions in V$_{15}$. To that purpose, we performed high-field electron spin resonance measurements at 120 GHz and extracted the resonance fields as a function of crystal orientation and temperature. The data are compared against simulations using exact diagonalization to obtain the parameters of the molecular spin Hamiltonian.

Domaines: Physique Quantique [quant-ph]

M. Martens, J. van Tol, N. S. Dalal, S. Bertaina, B. Barbara, et al.. Anisotropy of the molecular magnet V$_{15}$ spin Hamiltonian detected by high-field electron spin resonance. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2014, 89 (19), pp.195439. ⟨10.1103/PhysRevB.89.195439⟩. ⟨hal-01334185⟩