Witnessing entanglement in quantum magnets using neutron scattering
Allen Scheie, Pontus Laurell, Anjana Samarakoon, B. Lake, S. E. Nagler, G. E. Granroth, Satoshi Okamoto, Gonzalo A. Álvarez, D. M. Tennant
Abstract
Measuring quantum entanglement in solid state systems has been a long-standing challenge. Here, the authors use three entanglement witnesses borrowed from quantum information theory to directly detect quantum entanglement in the 1D Heisenberg spin chain system KCuF${}_{3}$ using inelastic neutron scattering data. The results are validated using density matrix renormalization group calculations and show that model-independent measures of quantum spin entanglement are experimentally possible, as well as reveal which witnesses are more experimentally robust.
Topics & Concepts
Quantum entanglementSpinonPhysicsQuantum mechanicsSquashed entanglementDensity matrix renormalization groupAmplitude damping channelQuantum discordEntanglement witnessSpin (aerodynamics)QuantumHeisenberg modelAntiferromagnetismThermodynamicsQuantum many-body systemsPhysics of Superconductivity and MagnetismAdvanced Condensed Matter Physics