Coherent manipulation of Zr(III) aryloxide qudits.

Paramagnetic molecules can serve as electron spin qubits for quantum information processing, provided that they preserve their spin coherence for a sufficient time to allow for computation and error correction. Here we report the rare isolation of stable Zr(III) aryloxide complexes, where Zr is an earth-abundant metal ion with a coherently manipulable electron spin. Density functional theory calculations reveal the trigonal planar d1 geometry stabilizes a 4dz2-5s hybrid singly occupied molecular orbital with little ligand contribution and significant s character (25-27%), yielding large isotropic hyperfine coupling constants of 803-809 MHz. We observed long spin-lattice relaxation times (T1) up to 87 ms and dephasing times (Tm, TmCPMG) up to 123 μs using isotope-selective pulsed electron paramagnetic resonance spectroscopy. Nutation experiments further showed coherent manipulation of several electronic and electronuclear transitions. This study introduces Zr(III) aryloxides as competitive molecular qudits and expands the scope of metal ions to more earth-abundant metals.