2008/11/30 by Animesh Datta, Sevag Gharibian · 6 citations
Computer Science · Mathematics · Physics and Astronomy · #Algorithm #Computation #Computer science #Interpretation (philosophy) #Mathematics #Measure (data warehouse) #Open quantum system #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum channel #Quantum computer #Quantum discord #Quantum information #Quantum mechanics #Quantum state #Quantum tomography #Qubit #State (computer science) #Statistical physics #Unitary state #quant-ph
paper · pdf · doi:10.1103/physreva.79.042325
published as Phys. Rev. A, 79, 042325, (2009) · Published version, containing additional discussion on the role of non-classicality in the locking of classical correlations
openalex publication_date 2009/04/17 · arxiv created 2009/04/18 · arxiv updated 2013/05/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate signatures of nonclassicality in quantum states, in particular, those involved in the DQC1 model of mixed-state quantum computation [E. Knill and R. Laflamme, Phys. Rev. Lett. 81, 5672 (1998)]. To do so, we consider two known nonclassicality criteria. The first quantifies disturbance of a quantum state under locally noneffective unitary operations (LNUs), which are local unitaries acting invariantly on a subsystem. The second quantifies measurement-induced disturbance (MID) in the eigenbasis of the reduced density matrices. We study the role of both figures of nonclassicality in the exponential speedup of the deterministic quantum computation with one qubit (DQC1) model and compare them vis-\`a-vis the interpretation provided in terms of quantum discord. In particular, we prove that a nonzero quantum discord implies a nonzero shift under LNUs. We also use the MID measure to study the locking of classical correlations [D. P. DiVincenzo et al., Phys. Rev. Lett. 92, 067902 (2004)] using two mutually unbiased bases (MUBs). We find the MID measure to exactly correspond to the number of locked bits of correlation. For three or more MUBs, it predicts the possibility of superior locking effects.