Unitary nn-designs via random quenches in atomic Hubbard and Spin models: Application to the measurement of R\'enyi entropies

We present a general framework for the generation of random unitaries based on random quenches in atomic Hubbard and spin models, forming approximate unitary $n$-designs, and their application to the measurement of R\'enyi entropies. We generalize our protocol presented in [Elben2017: arXiv:1709.05060, to appear in Phys. Rev. Lett.] to a broad class of atomic and spin lattice models. We further present an in-depth numerical and analytical study of experimental imperfections, including the effect of decoherence and statistical errors, and discuss connections of our approach with many-body quantum chaos.Comment: This is a new and extended version of the Supplementary material presented in arXiv:1709.05060v1, rewritten as a companion paper. Version accepted to Phys. Rev. A. Minus sign corrected in Eq (5

Towards a codification of practical knowledge

International audienceAs practical knowledge seems to have a central place in organisational issues, we focus on possibilities to study and formalize it. From an unusual theoretical perspective, we view practical knowledge as embodied knowing which only is only manifest through action in a particular situation. Although this knowledge is largely implicit, we try to make what is 'articulable' explicit. After highlighting the stakes involved in the codification of practices, we review the ontological and epistemological assumptions underlying the method developed. It is founded on participant observation, a video recording of a situated subjective perspective and an ex post interview using this perspective to aid an actor to make part of his/her practical knowledge explicit. We present its implementation within research on polar expeditions in order to understand how an experienced actor deals with risks. In conclusion, we point out (1) the importance of this kind of data in knowledge management, (2) some lines of further research

Zeeman slowers made simple with permanent magnets in a Halbach configuration

We describe a simple Zeeman slower design using permanent magnets. Contrary to common wire-wound setups no electric power and water cooling are required. In addition, the whole system can be assembled and disassembled at will. The magnetic field is however transverse to the atomic motion and an extra repumper laser is necessary. A Halbach configuration of the magnets produces a high quality magnetic field and no further adjustment is needed. After optimization of the laser parameters, the apparatus produces an intense beam of slow and cold 87Rb atoms. With a typical flux of 1 - 5 \times 10^10 atoms/s at 30 ms^-1, our apparatus efficiently loads a large magneto-optical trap with more than 10^10 atoms in one second, which is an ideal starting point for degenerate quantum gases experiments.Comment: 8+6 pages (article + appendices: calculation details, probe and oven description, pictures), 18 figures, supplementary material (movie, Mathematica programs and technical drawings

Measuring treatment satisfaction in MS: Is the Treatment Satisfaction Questionnaire for Medication fit for purpose?

BACKGROUND: The Treatment Satisfaction Questionnaire for Medication (TSQM) was designed to assess patient treatment satisfaction in chronic diseases. Its performance has not been examined in multiple sclerosis (MS). The 14 items of the TSQM cover four domains: Effectiveness, Side Effects, Convenience, and Global Satisfaction. OBJECTIVE: To evaluate performance of the TSQM in patients with relapsing MS, using data collected from the TENERE study (NCT00883337), in which 324 patients received oral teriflunomide or subcutaneous interferon beta-1a for ⩾48 weeks. METHODS: Five measurement properties were examined using traditional psychometric methods: data completeness, scale-to-sample targeting, scaling assumptions, reliability (including test-retest), and construct validity (internal: item-level scaling success, confirmatory factor analysis, and exploratory factor analysis; external: convergence, discrimination, and group differences). RESULTS: There were few ( 0.90). Internal validity tests supported item groupings. Correlations supported convergent and discriminant construct validity; hypothesis testing supported group differences validity. CONCLUSION: This investigation found the TSQM to be a useful tool, exhibiting good psychometric measurement properties in patients with relapsing MS in the TENERE study