2013/12/01 by Xiaojing Li, XIAO-JING LI, Huihui Ji +3
Computer Science · Physics and Astronomy · #Antiparallel (mathematics) #Condensed matter physics #Magnetic field #Negativity effect #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum discord #Quantum entanglement #Quantum mechanics #Qubit #Qutrit #Spin (aerodynamics)
paper · doi:10.1142/s0219749913500706
crossref issued 2013/12/01 · crossref published 2013/12/01 · crossref published-print 2013/12/01 · openalex publication_date 2013/12/01 · crossref published-online 2014/02/05 · crossref created 2014/02/05 · crossref deposited 2019/08/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/05/21 · crossref indexed 2026/08/03
The characterization of quantum discord (QD) has been well understood only for two-qubit states and is little known for mixed states beyond qubits. In this work, thermal quantum discord is studied for a qutrit system in different magnetic fields, where classical correlation and entanglement negativity are calculated for comparison. It is shown that the discord is more robust against temperature than the negativity. For a suitable region of magnetic field and its direction, the discord is non-zero while the negativity is zero. When the system is at a lower temperature, these three quantities, however, display a similar behavior for the varied field and direction, and their discontinuities come from crossovers between different ground states in the system. Moreover, the inequality between the quantum and classical correlations depends upon the system parameters as well as the temperature. In particular, both correlations are equal at a suitable field, direction, and temperature. Remarkably, such an equality remains for a strong field in the antiparallel direction, while both correlations in two-qubit systems are identical for any antiparallel field and temperature. These are useful for quantum information and understanding quantum correlations in qutrit mixed states.