Spin-Lattice Relaxation Decoherence Suppression in Vanishing Orbital Angular Momentum Qubits.

Multifrequency electron paramagnetic resonance spectroscopy on oriented single crystals of magnetically dilute Gd(III) ions in Gd 0.004 Y 0.996 (trensal) is used to determine the Hamiltonian parameters of the ground 8 S 7/2 term and its phase memory time, T m , characterizing its coherent spin dynamics. The vanishing orbital angular momentum of the 8 S 7/2 term makes it relatively insensitive to spin-lattice relaxation mediated by magnetoelastic coupling and leads to a T m of 12 μs at 3 K, which is not limited by spin-lattice relaxation.