Electron spin–lattice and spin–spin relaxation study of a trinuclear iron(iii) complex and its relevance in quantum computing

Abstract

Electron spins of molecular magnets are promising candidates for large scale quantum information processing because they exhibit a large number of low-lying excited states. In this paper X-band pulse electron paramagnetic resonance spectroscopy is used to determine the intrinsic relaxation times T₁ and T₂ of a molecular magnet with an S = 1/2 ground state, namely the neutral trinuclear oxo-centered iron(III) complex, [Fe₃(µ₃-O)(O₂CPh)₅(salox)(EtOH)(H₂O)]. The temperature dependence of the spin–lattice relaxation time T₁ between 4.5 and 11 K shows that the Orbach relaxation process is dominant with the first excited state lying 57 cm⁻¹ above the ground state, whereas the phase memory time T_M is of the order of 2.6 µs and exhibits a modest temperature dependence. These results together with previous magnetic measurements give further insight into the magnetic properties of the complex. The coherent manipulation of the electron spins is also examined by means of transient nutation experiments.