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An efficient scheme for numerical simulations of the spin-bath decoherence

V. V. Dobrovitski·H. A. De Raedt
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Abstract

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 than 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.

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V. V. Dobrovitski, H. A. De Raedt. 2003-01-23. An efficient scheme for numerical simulations of the spin-bath decoherence. https://doi.org/10.1103/physreve.67.056702

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