Observing Quantum Oscillation of Ground States in Single Molecular Magnet

Abstract

Single molecular magnets (SMMs) are among the potential systems for quantum memory and quantum information processing. Quantum coherence and oscillation are critical for these applications. The ground-state quantum coherence and Rabi oscillations of the SMM V15 ([V15(IV)As6(III)O42(H2O)]6-) have been studied in this context. We have affirmatively measured at 2.4 K the Rabi quantum oscillations and coherence time T2 for the ground states of the V15 ion of collective spin S=1/2, in addition to confirming the previously reported results for the S=3/2 excited states. The oscillations of S=3/2 and S=1/2 states are of different frequencies, and so can be separately selected for purposive manipulations. T2 of 188±4 ns (S=3/2) and 149±10 ns (S=1/2) are much less than T1∼12 μs and are further extendible via various approaches for qubit implementations.

Hyperfine Structure and Coherent Dynamics of Rare-Earth Spins Explored with Electron-Nuclear Double Resonance at Subkelvin Temperatures

“…For instance, the rapid increase of the nuclear spin relaxation time at sub-Kelvin temperatures, as observed in this study, is possible to provide some previously inaccessible ENDOR signals for the [NiFe]hydrogenase [48], and for the Mn cluster in Photosystem II [49]. Besides, a high degree of electron spin polarization at sub-Kelvin temperatures can also lead to an opportunity for the ground-spin-state investigation [50,51], and a complete characterization to the hyperfine coupling constants [52].…”

Room temperature quantum coherence in a potential molecular qubit

“…Surprisingly little has been published on quantum coherence times in mononuclear and polynuclear transition metal complexes 8,9 . In recent years, especially the quantum coherence in exchange coupled molecular nanomagnets (MNMs) has received much attention 8,[10][11][12][13][14][15][16][17][18][19][20][21][22] . The often stated advantage of such systems is the presence of additional spin states that can theoretically allow switching of the interqubit coupling 23 .…”

Engineering of entanglement and spin state transfer via quantum chains of atomic spins at large separations

“…For example, dynamical decoupling, which uses stroboscopic spin flips, gives an effective zero coupling to the environment 50 . This approach has already been applied to several solid state systems, for example, diamonds with nitrogen vacancy centers 51 , phosphorous donors in a silicon system 52 and proposed for molecular magnets 53 . We think that it deserves further applications for quantum spin chains supported on surfaces.…”