The entanglement of quantum objects can take surprising forms. Quantum physicists at the University of Innsbruck have investigated several flavors of entanglement in four trapped ions and report their results in the journal Nature Physics. Their study promotes further developments towards quantum computing and a deeper understanding of the foundations of quantum mechanics.
Multiparticle entanglement leads to richer correlations than two-particle entanglement and gives rise to striking contradictions with local realism1, inequivalent classes of entanglement2 and applications such as one-way or topological quantum computing3, 4. When exposed to decohering or dissipative environments, multiparticle entanglement yields subtle dynamical features and access to new classes of states and applications.