Density Distribution of a Bose-Einstein Condensate of Photons in a Dye-Filled Microcavity

The achievement of Bose-Einstein condensation of photons (phBEC) in a dye-filled microcavity has led to a renewed interest in the density distribution of the ideal Bose gas in a two-dimensional harmonic oscillator. We present measurements of the radial profile of photons inside the microcavity below and above the critical point for phBEC with a good signal-to-noise ratio. We obtain a good agreement with theoretical profiles obtained using exact summation of eigenstates.Comment: 5 pages, 4 figure

Density Distribution of a Bose-Einstein Condensate of Photons in a Dye-Filled Microcavity

The achievement of Bose-Einstein condensation of photons (phBEC) in a dye-filled microcavity has led to a renewed interest in the density distribution of the ideal Bose gas in a two-dimensional harmonic oscillator. We present measurements of the radial profile of photons inside the microcavity below and above the critical point for phBEC with a good signal-to-noise ratio. We obtain a good agreement with theoretical profiles obtained using exact summation of eigenstates.Comment: 5 pages, 4 figure

Coexistence of superfluid and Mott phases of lattice bosons

Recent experiments on strongly-interacting bosons in optical lattices have revealed the co-existence of spatially-separated Mott-insulating and number-fluctuating phases. The description of this inhomogeneous situation is the topic of this Letter. We establish that the number-fluctuating phase forms a superfluid trapped between the Mott-insulating regions and derive the associated collective mode structure. We discuss the interlayer's crossover between two- and three-dimensional behavior as a function of the lattice parameters and estimate the critical temperatures for the transition of the superfluid phase to a normal phase

The morphology and genesis of pseudogley phenomena in a Pleistocene loamy sand in the Netherlands.

[183.64:141.791]In a loamy sand profile with deep watertable, developed in Pleistocene deposits and showing mottling patterns and fine-textured bands and tongues, four soil-forming processes were recognizable: illuviation of fine clay and iron oxides, biological activity, pseudogleying, and breakdown of the clay fraction at the upper side of the illuviation horizon. The genesis of this soil can be explained by assuming that soil formation started where frost wedges occurred in the profile during the late Pleistocene and proceeded further at these points than in other parts of the soil. (Abstract retrieved from CAB Abstracts by CABI’s permission

Role of interactions in 87Rb-40K Bose-Fermi mixtures in a 3d optical lattice

We investigate the effect of interspecies interaction on a degenerate mixture of bosonic 87Rb and fermionic 40K atoms in a three-dimensional optical lattice potential. Using a Feshbach resonance, the 87Rb-40K interaction is tuned over a wide range. Through an analysis of the 87Rb momentum distribution, we find a pronounced asymmetry between strong repulsion and strong attraction. In the latter case, the Bose-Hubbard parameters are renormalized due to self-trapping, leading to a marked shift in the superfluid to Mott insulator transition with increasing Bose-Fermi interaction.Comment: 5 pages, 4 figure

Modelling and experiments of self-reflectivity under femtosecond ablation conditions

We present a numerical model which describes the propagation of a single femtosecond laser pulse in a medium of which the optical properties dynamically change within the duration of the pulse. We use a Finite Difference Time Domain (FDTD) method to solve the Maxwell's equations coupled to equations describing the changes in the material properties. We use the model to simulate the self-reflectivity of strongly focused femtosecond laser pulses on silicon and gold under laser ablation condition. We compare the simulations to experimental results and find excellent agreement.Comment: 11 pages, 8 figure

Race/Ethnicity in Candidate Experiments:a Meta-Analysis and the Case for Shared Identification

Does race/ethnicity effect how voters assess political candidates? To address this question, we pooled data from 43 published candidate experiments from the last 10 years with a combined N of 305,632. We distinguish three different schools of thought that authors apply: unjust stereotypes, useful stereotypes and shared identification. Voters use “unjust stereotypes” and discriminate against candidates of color or use “useful stereotypes” that inform them of the policy positions they expect candidates to defend. Scholars increasingly apply a “shared identification” perspective and study the effect of congruence between voter and candidate characteristics on assessments. The results show that voters do not assess racial/ethnic minority candidates differently than their majority (white) counterparts. This does not hold for Asian candidates in the US: voters assess them slightly more positively than majority candidates, although this effect is small (0.76 percentage points). Shared identification matters enormously: when voters share the same race/ethnicity as a candidate they assess them 7.9 percentage points higher than that they assess majority candidates. This effect is substantively meaningful and significant for all most researched (US-based) races/ethnicities. This indicates that the underrepresentation of racial/ethnic minority citizens cannot be explained by voting behavior, but possibly by supply side effects