# Hannover 2010 – wissenschaftliches Programm

## Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

# Q: Fachverband Quantenoptik und Photonik

## Q 4: Quantum Information: Concepts and Methods I

### Q 4.1: Vortrag

### Montag, 8. März 2010, 14:00–14:15, E 214

**A novel number operator-annihilation operator uncertainty relation and its use for entanglement detection** — •Iñigo Urizar Lanz^{1} and Geza Toth^{1,2,3} — ^{1}Theoretical Physics, The University of the Basque Country, E-48080 Bilbao, Spain — ^{2}IKERBASQUE, Basque Foundation for Science, E-48011 Bilbao, Spain — ^{3}Research Institute for Solid State Physics and Optics, H-1525 Budapest, Hungary

We consider the number operator-annihilation operator uncertainty as a well behaved alternative of the number-phase uncertainty relation, and examine its properties. We find a formulation in which the bound on the product of uncertainties depends on the expectation value of the particle number. Thus, while the bound is not a constant, it is a quantity that can be easily controlled in many systems. The uncertainty relation is approximately saturated by number-phase intelligent states. It allows us to define amplitude squeezing, connecting coherent states to Fock states, without a reference to a phase operator. We consider using the uncertainty relation for entanglement detection.