QUROPE Quantum Information Processing and Communication in Europe

E. G. Brow, W. Donnelly, A. Kempf, R. B. Mann, E. Martín-Martínez, and N. C. Menicucci
New Journal of Physics 16, 105020 (2014)

Entanglement farming is a protocol that involves successively sending pairs of “particle detectors” (such as atoms, ions, molecules, etc) transversely through an optical cavity. As pair after pair traverses the cavity, the field approaches a fixed-point state, where every pair of atoms emerges from the cavity in the same state, which is generically entangled. The fixed point is generally stable to small changes in the parameters.

E.  M. Kessler, P. Kómár, M. Bishof, L. Jiang, A.  S. Sørensen, J. Ye, M.  D. Lukin
Phys. Rev. Lett. 112, 190403 (2014)

The improvement of frequency standards using quantum resources, such as entanglement has been actively explored in recent years. The use of entangled resources, in principle, allows one to surpass the classical limit on precision. However, a characterization of the improvement obtainable by using entanglement requires a detailed investigation of the decoherence present in the system.

R. Demkowicz-Dobrzański, L. Maccone
Phys. Rev. Lett. 113, 250801 (2014)

Quantum metrology provides super-classical scaling in measurement precision by exploiting quantum effects. A crucial question in the field is to understand when entangled states lead to super-classical scaling.

U. Vazirani, T. Vidick
Phys. Rev. Lett. 113, 140501 (2014)