On the influence of resonance photon scattering on atom interference

Here, the influence of resonance photon-atom scattering on the atom interference pattern at the exit of a three-grating Mach-Zehnder interferometer is studied. It is assumed that the scattering process does not destroy the atomic wave function describing the state of the atom before the scattering process takes place, but only induces a certain shift and change of its phase. We find that the visibility of the interference strongly depends on the statistical distribution of transferred momenta to the atom during the photon-atom scattering event. This also explains the experimentally observed (Chapman et al 1995 Phys. Rev. Lett. 75 2783) dependence of the visibility on the ratio d_p/\lambda_i = y'_{12} (2\pi/kd\lambda_i), where y'_{12} is distance between the place where the scattering event occurs and the first grating, k is the wave number of the atomic center-of-mass motion, $d$ is the grating constant and \lambda_i is the photon wavelength. Furthermore, it is remarkable that photon-atom scattering events happen experimentally within the Fresnel region, i.e. the near field region, associated with the first grating, which should be taken into account when drawing conclusions about the relevance of "which-way" information for the interference visibility.Comment: 9 pages, 1 figur

Coherence loss and revivals in atomic interferometry: A quantum-recoil analysis

The coherence effects induced by external photons coupled to matter waves inside a Mach-Zehnder three-grating interferometer are analyzed. Alternatively to atom-photon entanglement scenarios, the model considered here only relies on the atomic wave function and the momentum shift induced in it by the photon scattering events. A functional dependence is thus found between the observables, namely the fringe visibility and the phase shift, and the transversal momentum transfer distribution. A good quantitative agreement is found when comparing the results obtained from our model with the experimental data.Comment: 18 pages, 4 figure

Coherence loss and revivals in atomic interferometry: A quantum-recoil analysis

The coherence effects induced by external photons coupled to matter waves inside a MachZehnder three-grating interferometer are analyzed. Alternatively to atomphoton entanglement scenarios, the model considered here only relies on the atomic wavefunction and the momentum shift induced in it by the photon scattering events. A functional dependence is thus found between the observables, namely the fringe visibility and the phase shift, and the transversal momentum transfer distribution. Good quantitative agreement is found when comparing the results obtained from our model with the experimental data. © 2012 IOP Publishing Ltd.MD, MB and DA acknowledge support from the Ministry of Science of Serbia under Projects OI171005, OI171028 and III45016. ASS acknowledges support from the Ministerio de Econom´ıa y Competitividad (Spain) under Projects FIS2010-22082 and FIS2010-29596-C02-01, as well as for a “Ram´on y Cajal” Research Fellowship.Peer Reviewe

Quantum Systems on Linear Groups

Discussed are quantized dynamical systems on orthogonal and affine groups. The special stress is laid on geodetic systems with affinely-invariant kinetic energy operators. The resulting formulas show that such models may be useful in nuclear and hadronic dynamics. They differ from traditional Bohr-Mottelson models where SL$(n,\mathbb{R})$ is used as a so-called non-invariance group. There is an interesting relationship between classical and quantized integrable lattices

On Wheeler's delayed-choice Gedankenexperiment and its laboratory realization

Here, we present an analysis and interpretation of the experiment performed by Jacques et al. (2007 Science 315, 966), which represents a realization of Wheeler's delayed-choice Gedankenexperiment. Our analysis is based on the evolution of the photon state, since the photon enters into the Mach-Zehnder interferometer with a removable beam-splitter until it exits. Given the same incident photon state onto the output beam-splitter, BS_output, the photon's state at the exit will be very different depending on whether BS_output is on or off. Hence, the statistics of photon counts collected by the two detectors, positioned along orthogonal directions at the exit of the interferometer, is also going to be very different in either case. Therefore, it is not that the choice of inserting (on) or removing (off) a beam-splitter leads to a delayed influence on the photon behavior before arriving at the beam-splitter, but that such a choice influences the photon state at and after BS_output, i.e., after it has exited from the Mach-Zehnder interferometer. The random on/off choice at BS_output has no delayed effect on the photon to behave as a wave or a corpuscle at the entrance and inside the interferometer, but influences the subsequent evolution of the photon state incident onto BS_output.Comment: 7 pages, 4 figure

Non-entire functions of creation and annihilation operators and their relation to phase operator

On the coherent states vertical bar alpha GT any entire function of creation and annihilation operators may be defined. We show that it is not the case for non-entire functions. Use of vertical bar alpha GT LT alpha vertical bar as identity operator for a non-entire function may lead to contradictory results. On the example of the phase operator we show how these possible contradictions may be avoided. On the coherent states |alpha GT any entire function of creation and annihilation operators may be defined. We show that it is not the case for non-entire functions. Use of |alpha GT LT alpha| as identity operator for a non-entire function may lead to contradictory results. On the example of the phase operator we show how these possible contradictions may be avoided.12th Central European Workshop on Quantum Optics, Jun 06-09, 2005, Ankara, Turke

Outdoor human thermal comfort in local climate zones of Novi Sad (Serbia) during heat wave period

Urban climate monitoring system (UCMS) was established in Novi Sad (Serbia) in 2014 based on the Local Climate Zones (LCZs) classification system, GIS model calculations and field work. Seven built and two land cover LCZ types were delineated and 27 stations equipped with air temperature and relative humidity sensors were distributed across all LCZs. Suitability of the developed monitoring system for human outdoor thermal comfort research in different LCZs of the city and its surroundings was investigated during a heat wave period using Physiologically Equivalent Temperature (PET) index. During the daytime (night-time) the highest thermal loads are present in open midrise (compact midrise) LCZ, while the most comfortable is LCZ A (dense trees) during the whole day. In general, the highest thermal loads are obtained in midrise, followed by low-rise, sparsely built, low plants and dense trees LCZs. All LCZs (except LCZ A - dense trees) had higher PET when compared to LCZ D (LCZ D - low plants) during evening and nocturnal hours with maximum difference of 7.1 °C (00 UTC) between LCZ 2 (compact midrise) and LCZ D (low plants). Contrary to this, LCZ D (low plants) had higher PET compared to the majority of LCZs during the daytime with maximum difference of 8.5 °C (9 UTC) when compared to LCZ A (dense trees). Furthermore, the smallest thermal comfort differences during heat wave occurred between LCZs with similar structure (i.e. open low-rise and large low-rise, compact midrise and compact low-rise) and cover (i.e. sparsely built and low plants)

A monoclonal antibody to the rat Crry/p65 antigen, a complement regulatory membrane protein, stimulates adhesion and proliferation of thymocytes

A murine monoclonal antibody (mAb), 3F10, was produced by fusion of spleen cells obtained from mice immunized with a rat cortical thymic epithelial cell line (R-TNC.1) stimulated with interferon-gamma and P3X myeloma cells. 3F10 recognized an antigen expressed both on thymocytes and non-lymphoid cells in the thymus. Flow cytometry showed that 3F10 stained more than 98% thymocytes and 90% R-TNC.1 cells. Immunoprecipitation and Western blot studies demonstrated that 3F10 reacted with molecules of 55000 and 65000 MW from both thymocyte and R-TNC.1 cell lysates. 3F10 recognized the same antigen on Chinese hamster ovary cells transfected with rat Crry as did 5I2 mAb, confirming the specificity of 3F10 mAb for the rat homologue of mouse Crry/p65, a membrane-bound complement regulatory protein. 3F10 mAb induced homotypic aggregation of thymocytes and exhibited an additive effect on the aggregation evoked by phorbol myristate acetate. The aggregation was dependent on active cell metabolism, intact cytoskeleton, divalent cations and activation of protein phosphatases 1 and 2A (as assessed by use of okadaic acid). In contrast, H-7, HA1004 and genistein partially inhibited, whereas staurosporine potentiated the aggregation of thymocytes triggered by 3F10. 3F10 mAb also stimulated binding of thymocytes to the R-TNC.1 line. Both homotypic and heterotypic adhesive interactions are mediated by leucocyte function-associated antigen-1 (LFA-1). In addition, 3F10 stimulated proliferation of thymocytes induced by suboptimal concentrations of concanavalin A. These data suggest that rat Crry/p65 might be involved in the regulation of both cell adhesion and activation of thymocytes. This is a novel, non-complement-dependent function of Crry/p65

Uticaj stanja površine metala na sjaj i strukturu metalnih prevlaka. I deo, Površinska refleksija svetlosti

Mirror brightness of metal surfaces can be associated with the high degree of mirror reflection which approaches very nearly the ideal reflectance of the same metal. The samples of steel and copper are processed by electrochemical polisher in corresponding electrolytes for electrochemical polishing. On previously mechanically, and further electrochemically polished samples surface roughness and surface reflection were measured. The effect of decreasing surface roughness of electrochemically polished samples was shown compared to only mechanical polished samples. Following the changes in the relation of the mirror, the total and the diffuse reflection, it is confirmed that it came to significant increase of brightness of the surface polished by electrochemical method, compared to initial surface, both for steel samples and for copper samples.Ogledalski sjaj metalnih površina se može povezati sa visokim stepenom ogledalske refleksije koji se približava idealnoj refleksivnosti istog metala. Uzorci čelika i bakra su podvrgnuti elektrohemijskom glačanju u odgovarajućim elektrolitima za elektrohemijsko glačanje. Na prethodno mehanički, a zatim elektrohemijskim glačanim uzorcima merena je hrapavost površine i refleksija svetlosti. Pokazan je uticaj smanjenja površinske hrapavosti elektrohemijski glačanih uzoraka u odnosu na samo mehanički glačane uzorke. Prateći promene odnosa ogledalske, ukupne i difuzne refleksije potvrđeno je da je došlo do značajnog povećanja sjaja površine glačane elektrohemijskim putem u odnosu na polaznu površinu, kako za uzorke čelika tako i za uzorke bakra