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

TL;DR

This study uses high-field electron spin resonance to analyze the anisotropy in the spin Hamiltonian of the V$_{15}$ molecular magnet, revealing detailed intramolecular interactions crucial for understanding its quantum spin dynamics.

Contribution

The paper provides a precise analysis of the V$_{15}$ spin Hamiltonian anisotropy using high-field ESR and exact diagonalization, advancing understanding of its quantum behavior.

Findings

Identification of anisotropic parameters in V$_{15}$

Correlation of resonance data with spin Hamiltonian models

Enhanced understanding of quantum spin dynamics in V$_{15}$

Abstract

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.