Characterizing Two‐Qubit Non‐Classical Correlations and Non‐Locality in Mixed Local Dephasing Noisy Channels

• Published in: Annalen der Physik Vol. 534; no. 10
• Main Authors: Rahman, Atta Ur, Khedif, Youssef, Javed, Muhammad, Ali, Hazrat, Daoud, Mohammed
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.10.2022
• Subjects: Channels; local quantum Fisher information; local quantum uncertainty; Markovian dynamical maps; Noise measurement; non‐Markovian dynamical maps; Purity; Quantum entanglement; Qubits (quantum computing); static‐Ornstein Uhlenbeck noise; Uncertainty; uncertainty‐induced non‐locality
• ISSN: 0003-3804; 1521-3889
• DOI: 10.1002/andp.202200197

The dephasing effects of two independent local mixed static‐Ornstein Uhlenbeck (STC‐OUK) noisy channels on the dynamics of two‐qubit non‐classical correlations, non‐locality, and entanglement are addressed. Here, i) local quantum Fisher information; ii) local quantum uncertainty; iii) uncertainty‐induced non‐locality; iv) Bell non‐locality; and v) negativity to quantify two‐qubit non‐classical correlations, non‐locality and entanglement, respectively, and their loss under the influence of mixed noise are used. The findings show that measure (i) compared to measure (ii) remains more effective in demonstrating non‐classical correlations. For the two‐qubit state with maximum purity, measure (iii) remains less fragile to the mixed STC‐OUK noise than measure (iv) but gets more vulnerable as the initial purity of the two‐qubit state falls. It is intriguing that measures (i), (ii), and (v) completely freeze after a particular interval, yet measures (iii) and (iv) remains partially preserved indefinitely. When compared to other two‐qubit correlation quantifiers, measure (v) exhibits non‐Markovian behavior and the phenomenon of sudden death and birth. Markovian and non‐Markovian dynamical maps, and extended two‐qubit correlations, can be induced by optimizing the current configuration. Finally, under the influence of mixed dephasing effects, robust and strengthened quantum correlations beyond entanglement in the two‐qubit Werner state is shown. Schematic diagram of two non‐interacting qubits QA and QB when coupled with two independent classical fields CF‐OUK and CF‐STC, i.e., one with Ornstein Uhlenbeck (OUK) and other with Static (STC) noise. The blue wavy lines show the dynamics of two qubits while DOUK and e DSTC denote the dephasing effects of OUK and STC noise.