Quantum discord for a central two-qubit system coupled to an XY spin chain with multipartite interaction

• Published in: Physica. E, Low-dimensional systems & nanostructures Low-dimensional systems & nanostructures, 2012-09, Vol.46, p.218-223
• Main Authors: Qiu, Liang, Tang, Gang, Han, Kui, Qing Yang, Xian, Xi Wu, Yu, Ye, Bin
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electronics; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Materials science; Molecular electronics, nanoelectronics; Nanoscale materials and structures: fabrication and characterization; Physics; Quantum dots; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Specific phase transitions; Structural transitions in nanoscale materials
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2012.09.025

Quantum discord of two central qubits coupled to an XY spin chain with three-spin interaction in a transverse magnetic field is investigated. Quantum discord decreases dramatically around the critical point α=0.5 without the external magnetic field and around λ=1 without the three-spin interaction. Here, α denotes the strength of the three-spin interaction and λ is the strength of the external magnetic field. If the three-spin interaction is switched on, the significant change position of quantum discord has a 2α displacement from the original position. Our results reveal that quantum discord could be used to spotlight the critical point of quantum phase transition, detect both the existence and strength of three-spin interaction. The significant change position of quantum discord has a 2α (α denotes the strength of the three-spin interaction) displacement from the original position. [Display omitted] ► Quantum discord could be used to spotlight the critical point of quantum phase transition. ► Quantum discord could detect the existence and the strength of three-spin interaction. ► The effect of the parameters on quantum discord has also been considered.