Entanglement Generation
Entangled states are a fundamental resource in quantum-information and quantum-communication science. Additionally, certain entangled atomic states (also known as spin-squeezed states), in principle, allow us to significantly improve the resolution in Ramsey spectroscopy . However, in practice entangled states are difficult to prepare and maintain; noise and decoherence rapidly collapse them into classical statistical mixtures. Thus an important challenge is the design of robust and decoherence-resistant methods for entanglement generation.
Recently we have proposed the design of gapped Hamiltonians to create a protected manifold of multidegenerate levels. This design protects against local decoherence processes. We have used it for generating robust optical coherent states, or "cat states," in optical lattices and trapped ions.
PRA 76, 053617 (2007), PRA 76, 053617 (2007).
