Coherent dynamics and decoherence in a superconducting weak link

We demonstrate coherent dynamics of quantized magnetic fluxes in a superconducting loop with a weak link - a nanobridge patterned from the same thin NbN film as the loop. The bridge is a short rounded shape constriction, close to 10 nm long and 20 - 30 nm wide, having minimal width at its center. Quantum state control and coherent oscillations in the driven time evolution of the tunnel-junctionless system are achieved. Decoherence and energy relaxation in the system are studied using a combination of microwave spectroscopy and direct time-domain techniques. The effective flux noise behavior suggests inductance fluctuations as a possible cause of the decoherence.Comment: 5 pages, 3 figure

Production Asymmetry Measurement of High Xt Hadrons in pp Collisions at 40 GeV

Single-spin asymmetries for hadrons have been measured in collisions of transversely-polarized 40 GeV/c proton beam with an unpolarized liquid hydrogen target. The asymmetries were measured for pi+-, K+-, protons and antiprotons, produced in the central region (0.02 < Xf < 0.10 and 0.7 < Pt < 3.4 GeV/c). Asymmetries for pi+-, K+- and antiprotons show within measurement errors the linear dependence on Xt and change a sign near 0.37. For protons negative asymmetry, independent of Xt has been found. The results are compared with those of other experiments and SU(6) model predictions.Comment: 25 pages (Latex), 12 Postscript figure

Speckle photo electromotive force in CdTe:V and CdTe:Ge for measurement of vibration with large amplitude

The photo-electromotive force induced by a speckle pattern vibrating with large amplitude in photorefractive CdTe:V and CdTe:Ge is experimentally studied. This technique is shown to be suitable for transversal amplitude vibration measurement as well as for material response time and associated conductivity characterization. Experiments were carried out with 532 and 1064 nm wavelength illumination over a wide vibration frequency range. The results are in good agreement with a previously reported theoretical model. The studied doped crystals exhibit peculiar different features that are described and discussed