2000/12/04 by Antonio Acín, A. Acin, E. Jané +3 · 2 citations
Computer Science · Engineering · Mathematics · Physics and Astronomy · #Algorithm #Artificial intelligence #Computer science #Construct (python library) #Control (management) #Control theory (sociology) #Coordinate system #Engineering #Estimation #Mathematical optimization #Mathematics #Optimal estimation #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum mechanics #Space (punctuation) #Spin (aerodynamics) #State (computer science) #State space #Statistics #Transformation (genetics) #Unitary state #Unitary transformation #quant-ph
paper · pdf · doi:10.1103/physreva.64.050302
published as Phys. Rev. A 64, 050302(R) (2001). · 4 pages, REVTEX
arxiv created 2000/12/04 · openalex publication_date 2001/10/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We construct the optimal strategy for the estimation of an unknown unitary transformation U\ensuremath∈SU(d). This includes, in addition to a convenient measurement on a probe system, finding which is the best initial state on which U is to act. When U\ensuremath∈SU(2), such an optimal strategy can be applied to simultaneously estimate both the direction and the strength of a magnetic field, and shows how to use a spin 1/2 particle to transmit information about a whole coordinate system instead of only a direction in space.