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Enhancement of Macroscopic Quantum Tunneling by Landau-Zener Transitions

Joachim Ankerhold·Hermann Grabert
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Abstract

Motivated by recent realizations of qubits with a readout by macroscopic quantum tunneling in a Josephson junction, we study the problem of barrier penetration in presence of coupling to a spin-${1\over 2}$ system. It is shown that when the diabatic potentials for fixed spin intersect in the barrier region, Landau- -Zener transitions lead to an enhancement of the tunneling rate. The effect of these spin flips in imaginary time is in qualitative agreement with experimental observations.

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Joachim Ankerhold, Hermann Grabert. 2003-04-15. Enhancement of Macroscopic Quantum Tunneling by Landau-Zener Transitions. https://doi.org/10.1103/physrevlett.91.016803

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