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Coherence Window in the dynamics of Quantum Nanomagnets

P. C. E. Stamp·I. S. Tupitsyn
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Abstract

Decoherence in many solid-state systems is anomalously high, frustrating efforts to make solid-state qubits. We show that in nanomagnetic insulators in large transverse fields, there can be a fairly narrow field region in which both phonon and nuclear spin-mediated decoherence are drastically reduced. As examples we calculate decoherence rates for the $Fe$-8 nanomolecule, for $Ni$ particles, and for $Ho$ ions in $LiHo_xY_{1-z}F_4$. The reduction in the decoherence, compared to low field rates, can exceed 6 orders of magnitude. The results also give limitations on the observability of macroscopic coherence effects in magnetic systems.

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P. C. E. Stamp, I. S. Tupitsyn. 2003-09-12. Coherence Window in the dynamics of Quantum Nanomagnets. https://doi.org/10.1103/physrevb.69.014401

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