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arXiv · 2609.28180

Quantum dynamics of spinful impurity in ideal Bose gas

O. Hryhorchak·V. Pastukhov
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Abstract

We discuss the quench dynamics of an isolated system composed of a single spinful impurity in the transverse Rabi field and bath of non-interacting three- and two-dimensional bosons. Specifically, we consider the evolution of bosons and a spin-$\frac{1}{2}$ particle, initially prepared in a Bose-Einstein condensate state and a magnetic ground state, respectively, with the spin-dependent contact boson-impurity interaction switched on. Applying an original mean-field-like approximation, which naturally reflects the statistical effects of the bosonic bath, we calculate time-dependent components of the average impurity spin and the overlap of the wave function between initial and arbitrary time moments. A key prediction is a substantial speed-up in the decoherence (thermalization) dynamics of the spin degree of freedom compared to results obtained with the Chevy-like ansatz.

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O. Hryhorchak, V. Pastukhov. 2026-09-23. Quantum dynamics of spinful impurity in ideal Bose gas. https://arxiv.org/abs/2609.28180

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