Relative states, quantum axes, and quantum references

2005/08/25 by E. Bagán, E. Bagan, S. Iblisdir +2 · 2 citations
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.73.022341

published as Phys. Rev. A 73, 022341 (2006) · 6 pages, no figures

arxiv created 2005/08/25 · openalex publication_date 2006/02/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04

Abstract

We address the problem of measuring the relative angle between two ``quantum axes'' made out of N<sub>1</sub> and N<sub>2</sub> spins. Closed forms of our fidelitylike figure of merit are obtained for an arbitrary number of parallel spins. The asymptotic regimes of large N<sub>1</sub> and/or N<sub>2</sub> are discussed in detail. The extension of the concept ``quantum axis'' to more general situations is addressed. We give optimal strategies when the first quantum axis is made out of parallel spins whereas the second is a general state made out of two spins.

Citations

• Optimal measurements for relative quantum information
• Random subspaces for encryption based on a private shared Cartesian frame
• Classical and Quantum Communication without a Shared Reference Frame

Cited by

• Modes of asymmetry: The application of harmonic analysis to symmetric quantum dynamics and quantum reference frames
• Multicopy programmable discrimination of general qubit states