2000/04/25 by Holger Mack, Dietmar Fischer, Dietmar G. Fischer +1
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.1103/physreva.62.042301
published as Phys. Rev. A 62, 042301 (2000) · 6 pages, including 3 figures
arxiv created 2000/04/25 · openalex publication_date 2000/09/05 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We analyze the estimation of a finite ensemble of quantum bits that have been sent through a depolarizing channel. Instead of using the depolarized qubits directly, we first apply a purification step and show that this improves the fidelity of subsequent quantum estimation. Even though we lose some qubits of our finite ensemble the information is concentrated in the remaining purified ones.