Efficient variational approach to dynamics of a spatially extended bosonic Kondo model

摘要: We develop an efficient variational approach to studying dynamics of a localized quantum spin coupled bath mobile spinful bosons. use parity symmetry decouple the impurity from environment via canonical transformation and reduce problem model interacting bosonic bath. describe coherent time evolution latter using Gaussian states as ansatz. provide full analytical expressions for equations describing that can be applied study in- out-of-equilibrium phenomena in wide class problems. In accompanying paper [Y. Ashida {\it et al.}, Phys. Rev. Lett. 123, 183001 (2019)], we present concrete application this general formalism analysis Rydberg Central Spin Model, which spin-1/2 undergoes spin-changing collisions dense cloud two-component ultracold To illustrate new features arising orbital motion atoms, compare our results Monte Carlo with spatially bosons bath, random positions atoms give rise couplings standard central model.