Abstract: This paper investigates the evolution characteristics of thermal entanglement and quantum correlations in a two-qubit non-Hermitian Heisenberg model under a real magnetic field. By introducing the biorthogonal basis, the influence of real magnetic field on the energy spectrum structure of the system is analyzed, and the time evolution behaviors of thermal entanglement and quantum correlations are explored. It is found that the introduction of a real magnetic field can change the energy-level structure of the system, leading to the disappearance of energy-level exceptional points and the intensification of energy-level splitting. Regarding thermal entanglement, when no real magnetic field is applied, the system exhibits a sudden transition of entanglement at the exceptional points, however, after applying a real magnetic field, this phenomenon disappears, and the real magnetic field can enhance the entanglement characteristics of the system within a certain range. In the study of the time evolution of quantum correlations, significant differences in the time evolution trends of entanglement are observed with and without a real magnetic field, and the real magnetic field enables the system to maintain stable entanglement during long-term evolution and retain robust entanglement properties. These findings indicate that a real magnetic field is significant for entanglement regulation in non-Hermitian systems, providing new theoretical support for the research on non-Hermitian quantum information processing.

Key words: quantum information, non-Hermitian, quantum spin system, quantum entanglement