Heralded Entanglement between Atomic Ensembles: Preparation, Decoherence, and Scaling

Heralded entanglement between collective excitations in two atomic ensembles is probabilistically generated, stored, and converted to single photon fields. By way of the concurrence, quantitative characterizations are reported for the scaling behavior of entanglement with excitation probability and for the temporal dynamics of various correlations resulting in the decay of entanglement. A lower bound of the concurrence for the collective atomic state of 0.9\pm 0.3 is inferred. The decay of entanglement as a function of storage time is also observed, and related to the local dynamics.Comment: 4 page

Quantum Key Distribution Using Quantum Faraday Rotators

We propose a new quantum key distribution (QKD) protocol based on the fully quantum mechanical states of the Faraday rotators. The protocol is unconditionally secure against collective attacks for multi-photon source up to two photons on a noisy environment. It is also robust against impersonation attacks. The protocol may be implemented experimentally with the current spintronics technology on semiconductors.Comment: 7 pages, 7 EPS figure

Characterisation of the dynamical quantum state of a zero temperature Bose-Einstein condensate

We describe the quantum state of a Bose-Einstein condensate at zero temperature. By evaluating the Q-function we show that the ground state of Bose-Einstein condensate under the Hartree approximation is squeezed. We find that multimode Schroedinger cat states are generated as the condensate evolves in a ballistic expansion.Comment: 13 pages, 6 figure

Effect of alum (top-dressed and mixed) with rice hulls on pH and ammonia emissions from poultry houses

The use of aluminum sulfate [alum; Al2(SO3)4·14H2O] as top dressing to poultry litter has been proven in reducing ammonia (NH3) volatilization under both laboratory and field tests; however, there has been no information of alum application in mixing methods from poultry litter or rice hulls. The aim of the experiment was to evaluate the effects of alum top dressed or mixed with rice hulls as litter management methods on pH and NH3 emissions. A total of 180 broiler chickens were randomly allocated to 12 pens to a density of 0.07 m2/bird for 5 weeks, creating 4 replicates of 3 experimental treatments with 15 birds per experimental unit as a completely randomized design. The treatments included an untreated control, 100 g of alum (top dressing) and 100 g of alum (mixed)/kg of rice hull. In addition, alum treatment was usually applied by top dressing onto the rice hulls or fully mixed with the rice hulls. During the experimental period, pH and NH3 emissions were significantly reduced by the two different methods of alum amendments (P < 0.05) in the litter over time compared with the controls except for NH3 emissions at 1 through 3 weeks. However, no significant differences (P > 0.05) in pH and NH3 emission were observed between the two different methods with alum for 5 weeks. The reduction in NH3 emission from 100 g of alum top-dressed and 100 g of alum fully mixed with kg of rice hull at 5 weeks was 50 and 51%, respectively. In summary, these results indicate that “mixing” methods of alum as well as top dressing would serve as a suitable method for decreasing NH3 emission, which resulted in lower pH.Key words: Alum, top dressing, mixing, pH, ammonia

Ku-band system design study and TDRSS interface analysis

The capabilities of the Shuttle/TDRSS link simulation program (LinCsim) were expanded to account for radio frequency interference (RFI) effects on the Shuttle S-band links, the channel models were updated to reflect the RFI related hardware changes, the ESTL hardware modeling of the TDRS communication payload was reviewed and evaluated, in LinCsim the Shuttle/TDRSS signal acquisition was modeled, LinCsim was upgraded, and possible Shuttle on-orbit navigation techniques was evaluated