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arXiv · 2205.01208

Decoherence and energy flow in the sunburst quantum Ising model

Alessio Franchi·Davide Rossini·Ettore Vicari
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Abstract

We study the post-quench unitary dynamics of a quantum sunburst spin model, composed of a transverse-field quantum Ising ring which is suddenly coupled to a set of independent external qubits along the longitudinal direction, in a way to respect a residual translation invariance and the Ising $\mathbb{Z}_2$ symmetry. Starting from the different equilibrium quantum phases of the system, we characterize the decoherence and the energy storage in the external qubits, which may be interpreted as a probing apparatus for the inner Ising ring. Our results show that, in proximity of the quantum transitions of the Ising ring, either first-order or continuous, it is possible to put forward dynamic FSS frameworks which unveil peculiar scaling regimes, depending on the way in which the large-size limit is taken: either by fixing the number $n$ of probing qubits, or their interspace distance $b$. In any case, the dependence of the various observables on $n$ can be reabsorbed into a redefinition of the quench parameter by a $\sqrt{n}$ prefactor. We also address the role of a nearest-neighbor coupling between the external qubits.

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Alessio Franchi, Davide Rossini, Ettore Vicari. 2022-05-02. Decoherence and energy flow in the sunburst quantum Ising model. https://doi.org/10.1088/1742-5468%2Fac8284

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