Electron spin resonance work shows how transition metal can retain quantum information, important work on the path to next-generation quantum technologies.

Enabling the rational synthesis of molecular candidates for quantum information processing requires design principles that minimize electron spin decoherence. Two series of paramagnetic coordination complexes, [M(C2O4)3]3- (M = Ru, Cr, Fe) and [M(CN)6]3- (M = Fe, Ru, Os), were prepared and subsequently interrogated by pulsed electron paramagnetic resonance spectroscopy to assess quantitatively the influence of the magnitude of spin (S = 1/2, 3/2, 5/2) and spin–orbit coupling (ζ = 464, 880, 3100 cm–1) on decoherence. The results illustrate that the design of qubit candidates can be achieved with a wide range of paramagnetic ions and spin states while preserving a long-lived coherence.

Measurements performed in the EMR program demonstrate that the nuclear spins associated with donor states in silicon field-effect transistors can be polarized at high magnetic fields by controlling the current and gate voltage on the device, i.e., the nuclear polarization can be controlled purely by electrical means.