Qubit dynamics with classical noise

Autor: Qin Huang, Marco Merkli
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Physics Open, Vol 5, Iss , Pp 100043- (2020)
Druh dokumentu: article
ISSN: 2666-0326
DOI: 10.1016/j.physo.2020.100043
Popis: We study the evolution of a qubit evolving according to the Schrödinger equation with a Hamiltonian containing noise terms, modeled by random diagonal and off-diagonal matrix elements. We show that the noise-averaged qubit density matrix converges to a final state, in the limit of large times t. The convergence speed is polynomial in 1/t, with a power depending on the regularity of the noise probability density and its low frequency behaviour. We evaluate the final state explicitly. We show that in the two regimes of weak and of strong off-diagonal noise, the process implements the dephasing channel in the energy- (localized) and the delocalized basis, respectively.
Databáze: Directory of Open Access Journals