Magnetic Susceptibility as a Macrosopic Entaglement Witness
Author(s): M. Wieśniak, V. Vedral, Č. Brukner
Journal: New Journal of Physics
DOI Number: 10.1088/1367-2630/7/1/258
Link: Link to publication
We show that magnetic susceptibility can reveal spin entanglement between individual constituents of a solid, while magnetization describes their local properties. We then show that magnetization and its variance (equivalent to magnetic susceptibility for a wide class of systems) satisfy complementary relation in the quantum-mechanical sense. It describes sharing of (quantum) information in the solid between spin entanglement and local properties of its individual constituents. Magnetic susceptibility is shown to be a macroscopic (thermodynamical) spin entanglement witness that can be applied without complete knowledge of the specific model (Hamiltonian) of the solid.