Efficient scheme for numerical simulations of the spin-bath decoherence

V. V. Dobrovitski, H. A. De Raedt
2003 Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics  
We demonstrate that the Chebyshev expansion method is a very efficient numerical tool for studying spin-bath decoherence of quantum systems. We consider two typical problems arising in studying decoherence of quantum systems consisting of few coupled spins: (i) determining the pointer states of the system, and (ii) determining the temporal decay of quantum oscillations. As our results demonstrate, for determining the pointer states, the Chebyshev-based scheme is at least a factor of 8 faster
more » ... n existing algorithms based on the Suzuki-Trotter decomposition. For the problems of second type, the Chebyshev-based approach has been 3--4 times faster than the Suzuki-Trotter-based schemes. This conclusion holds qualitatively for a wide spectrum of systems, with different spin baths and different Hamiltonians.
doi:10.1103/physreve.67.056702 pmid:12786317 fatcat:f5lvxysjr5bt5fvusol3t5tt7q