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 GdY(trensal) is used to determine the Hamiltonian parameters of the ground term and its phase memory time, , characterizing its coherent spin dynamics. The vanishing orbital angular momentum of the term makes it relatively insensitive to spin-lattice relaxation mediated by magnetoelastic coupling and leads to a of 12 μs at 3 K, which is not limited by spin-lattice relaxation.