2006/06/30 by Christian D'Cruz, Christian D’Cruz, Tobias J. Osborne +2
Computer Science · Mathematics · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Characterization (materials science) #Combinatorics #Discrete mathematics #Mathematical analysis #Mathematical physics #Mathematics #Physics #Pure mathematics #Quantum Information and Cryptography #Quantum Mechanics and Applications #Representation theorem #State (computer science) #Subspace topology #TRACE (psycholinguistics) #quant-ph
paper · pdf · doi:10.1103/physrevlett.98.160406
published as Phys. Rev. Lett. 98, 160406 (2007) · 4 pages, 2 figures
arxiv created 2007/03/08 · openalex publication_date 2007/04/19 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We formulate and prove a de Finetti representation theorem for finitely exchangeable states of a quantum system consisting of k infinite-dimensional subsystems. The theorem is valid for states that can be written as the partial trace of a pure state |Psi/Psi| chosen from a family of subsets Cn of the full symmetric subspace for n subsystems. We show that such states become arbitrarily close to mixtures of pure power states as n increases. We give a second equivalent characterization of the family Cn.