We study the relaxation of the local ferromagnetic order in the quantum Ising chain in a slant field with both longitudinal and transverse components. After preparing the system in a fully polarised state, we analyse the time evolution of the entire probability distribution function (PDF) of the magnetisation within a block of ℓ spins. We first analyse the effect of confinement on the Gaussification of the PDF for large ℓ, showing that the melting of initial order is suppressed when the longitudinal field is aligned to initial magnetisation while it is speed up when it is in the opposite direction. Then we study the thermalisation dynamics. In the paramagnetic region, the PDF quickly shows thermal features. Conversely, in the ferromagnetic phase, when confinement takes place, the relaxation suffers a typical slowing down which depends on the interplay between the strength of the longitudinal field, the density of excitations, and the direction of the initial polarisation. Even when the initial magnetisation is aligned oppositely to the longitudinal field, confinement prevents thermalisation in the accessible timescale, as it is neatly bared by the PDF.
We use a noisy signal with finite correlation time to drive a spin (dissipative impurity) in the quantum XY spin chain and calculate the dynamics of entanglement entropy (EE) of a bipartition of spins, for a stochastic quantum trajectory. We compute the noise averaged EE of a bipartition of spins and observe that its speed of spreading decreases at strong dissipation, as a result of the Zeno effect. We recover the Zeno crossover and show that noise averaged EE can be used as a proxy for the heating and Zeno regimes. Upon increasing the correlation time of the noise, the location of the Zeno crossover shifts at stronger dissipation, extending the heating regime.
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