Spin-Lattice Relaxation and Spin-Phonon Coupling of s Metal Ions at the Surface.

To use transition metal ions for spin-based applications, it is essential to understand fundamental contributions to electron spin relaxation in different ligand environments. For example, to serve as building blocks for a device, transition metal ion-based molecular qubits must be organized on surfaces and preserve long electron spin relaxation times, up to room temperature. Here we propose monovalent group 12 ions (Zn and Cd) as potential electronic metal qubits with an s ground state. The relaxation properties of Zn and Cd, stabilized at the interface of porous aluminosilicates, are investigated and benchmarked against vanadium (3d) and copper (3d) ions. The spin-phonon coupling has been evaluated through DFT modeling and found to be negligible for the s states, explaining the long coherence time, up to 2 μs, at room temperature. These so far unexplored metal qubits may represent viable candidates for room temperature quantum operations and sensing.