Evaluation of the viability of [V(C8S8)3]2– as a qubit in protiated, deuterated,
and nuclear spin-free solvents. (a) The Hahn echo decay curve for 1′ at 10 K in CS2 indicates the time frame
for the loss of quantum information from the spin qubit. The red line
is a biexponential fit that quantifies the time constant for this
decay, T2, of 675(7) μs. The fast
decay at 2τ < 0.1 ms is attributed to a small percentage
of closely spaced [V(C8S8)3]2– moieties that occur due to the inability of CS2 to form a frozen glass. (b) Logarithmic temperature dependence
of T2 for [V(C8S8)3]2– in protiated, deuterated, and
nuclear spin-free solvents, which illustrates the enormous impact
of eliminating nuclear spins on the magnitude of the coherence time.