Quantum discord for two-qubit CS states: Analytical solution

2013/02/21 by M. A. Yurishchev, Yurishchev, M. A. · 1 citation
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Quantum and electron transport phenomena #Statistical Mechanics (cond-mat.stat-mech)

paper · pdf · doi:10.48550/arxiv.1302.5239

openalex publication_date 2013/02/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We found an universal local unitary (orthogonal) transformation which transforms any centrosymmetric (CS) density matrix ρ_CS into the X density matrix ρ_X: H⊗ Hρ_CSH⊗ H=ρ_X, where H is the Hadamard transformation. Because quantum discord is invariant under the local unitary transformations, this remarkable property allows to get the discord of general two-qubit CS states in the analytical form using the corresponding well-known formulas for the X states. Examples of systems with CS density matrices provided from the recent literature, including XXZ spin model with the Dzyaloshinsky-Moriya interaction, a gas of spin-carrying particles in closed nanopore, and a family of pseudopure states.

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• Geometric measure for two-qubit CS-states: an exactly solvable model

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