Diverging Entanglement Length in Gapped Quantum Spin Systems 论文

详细信息

发表期刊/会议

Physical Review Letters

发表日期

2004-02-23

发表年份

2004

摘要

We prove the existence of gapped quantum Hamiltonians whose ground states exhibit an infinite entanglement length, as opposed to their finite correlation length. Using the concept of entanglement swapping, the localizable entanglement is calculated exactly for valence bond and finitely correlated states, and the existence of the so-called string-order parameter is discussed. We also report on evidence that the ground state of an antiferromagnetic chain can be used as a perfect quantum channel if local measurements on the individual spins can be implemented.