- Mathematical aspects of identifying entangled quantum states (entanglement witnesses, nonlinear entanglement criteria, spin squeezing inequalities)
- Methods for the experimental creation and detection of entanglement in quantum optical systems (photonic systems, spin squeezing in cold atomic ensembles, optical lattices of cold atoms)
- Multi-particle singlet states in cold gases (see link at Morgan W. Mitchell's group)
- Multi-particle entanglement of Dicke states
- Scalable state tomography (Permutationally Invariant Quantum Tomography)
- Application of entangled quantum states for quantum metrology (e.g., differential magnetometry with cold atomic ensembles)
- Quantum Fisher Information and its relation to multipartite entanglement
- Foundations of quantum theory (Bell inequalities and local hidden variable models)
1. Polytope of separable states for the Optimal Spin Squeezing Inequalities. [Figure from Phys. Rev. Lett. 99, 25045 (2007); Phys. Rev. A 79, 042334 (2009).] 2. Setup generating a four-qubit symmetric Dicke state with two excitations with parametric down-conversion in a BBO crystal, linear optical elements and detectors. [Figure from Phys. Rev. Lett. 98, 063604 (2007).] 3. Results of Permutationally Invariant Tomography in a four-photon experiment [Figure from Phys. Rev. Lett. 105, 250403 (2010).] |