2016/02/15 by Chien-Chang Chen, Chien‐Chang Chen, Hsi‐Sheng Goan +1
Computer Science · Mathematics · Physics and Astronomy · #Bloch sphere #Computer science #Formalism (music) #Mathematics #Open system (computing) #Perturbation (astronomy) #Physics #Population #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum mechanics #Quantum state #Quantum system #Qubit #Spectroscopy and Quantum Chemical Studies #Statistical physics #TRACE (psycholinguistics) #Trace distance #cond-mat.mes-hall #cond-mat.stat-mech #quant-ph
paper · pdf · doi:10.1103/physreva.93.032113
published as Physical Review A 93, 032113 (2016) · 15 pages, 8 figures; accepted for publication in Phys. Rev. A
arxiv created 2016/02/15 · openalex publication_date 2016/03/09 · arxiv updated 2016/04/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We investigate the preparation of a target initial state for a two-level (qubit) system from a system-environment equilibrium or correlated state by an external field. The system-environment equilibrium or correlated state results from the inevitable interaction of the system with its environment. An efficient method in an extended auxiliary Liouville space is introduced to describe the dynamics of the non-Markovian open quantum system in the presence of a strong field and an initial system-environment correlation. By using the time evolutions of the population difference, the state trajectory in the Bloch sphere representation, and the trace distance between two reduced system states of the open quantum system, the effect of initial system-environment correlations on the preparation of a system state is studied. We introduce an upper bound and a lower bound for the trace distance within our perturbation formalism to describe the diverse behaviors of the dynamics of the trace distance between various correlated states after the system state preparation. These bounds, that are much more computable than similar bounds in the literature, give a sufficient condition and a necessary condition for the increase of the trace distance and are related to the witnesses of non-Markovianity and initial system-bath correlation.