Floquet engineering of correlated tunneling in the Bose-Hubbard model with ultracold atoms

We report on the experimental implementation of tunable occupation-dependent tunneling in a Bose-Hubbard system of ultracold atoms via time-periodic modulation of the on-site interaction energy. The tunneling rate is inferred from a time-resolved measurement of the lattice site occupation after a quantum quench. We demonstrate coherent control of the tunneling dynamics in the correlated many-body system, including full suppression of tunneling as predicted within the framework of Floquet theory. We find that the tunneling rate explicitly depends on the atom number difference in neighboring lattice sites. Our results may open up ways to realize artificial gauge fields that feature density dependence with ultracold atoms.Comment: 8 pages, 9 figure

"Minimal metabolism": A key concept to investigate the origins and nature of biological systems

The systems view on life and its emergence from complex chemistry has remarkably increased the scientific attention on metabolism in the last two decades. However, during this time there has not been much theoretical discussion on what constitutes a metabolism and what role it actually played in biogenesis. A critical and updated review on the topic is here offered, including some references to classical models from last century, but focusing more on current and future research. Metabolism is considered as intrinsically related to the living but not necessarily equivalent to it. More precisely, the idea of "minimal metabolism", in contrast to previous, top-down conceptions, is formulated as a heuristic construct, halfway between chemistry and biology. Thus, rather than providing a complete or final characterization of metabolism, our aim is to encourage further investigations on it, particularly in the context of life's origin, for which some concrete methodological suggestions are provided.This work was carried out as part of a Horizon 2020 Marie Curie ITN ("ProtoMet"-Grant Agreement no. 813873 with the European Commission), within which NL obtained a PhD fellowship. KR-M also acknowledges support from the Basque Government (Grant IT 122819) and the Spanish Ministry of Science and Innovation (PID2019-104576GB-I00

Patterns of inpatient care for immigrants in Switzerland: A case control study

Background: Migration has become a major political and social concern in West European societies. Methods: A case-control method was used to analyse the utilisation of inpatient mental health services by immigrants from a catchment area in Switzerland over a 7-year period. Results: Compared to natives, immigrants had fewer psychiatric hospitalisations, but more emergency and compulsory admissions. During inpatient treatment, they received less psycho-, ergo- and physiotherapy. Other therapies as well as compulsory measures were at comparable rates, as was the frequency of irregular discharge. They spent shorter periods as inpatients and the rate of psychiatric readmissions was significantly lower. Comparison of different countries of origin revealed that only patients from West and North Europe were comparable to natives regarding type of referral, inpatient treatment, and longitudinal measures of service utilisation. Even after accounting for effects of social class, immigrants from South Europe, former Yugoslavia, Turkey, East Europe and more distant countries spent significantly shorter time in inpatient treatment, compared to Swiss control patients. Conclusions: Results of this study clearly point to an underutilisation of inpatient facilities among immigrants with mental disorders, and to disadvantages in psychiatric inpatient care. This, however, does not pertain to all foreign patients to the same extent: inequalities of mental health service use are particularly pronounced in immigrants from more distant countrie

Is there an impact of global and local disasters on psychiatric inpatient admissions?

Abstract. : Background: : Disasters of the magnitude of September 11, 2001 have a serious public health impact. By dominating media broadcasts, this effect is not limited to the site of the disaster. We tested the hypothesis whether such extraordinary burden results in an increase of psychiatric inpatient treatment. As such we analysed all psychiatric inpatient admissions in the Canton of Zurich/Switzerland. To test the influence of proximity to a disaster, we additionally analysed the impact of a local amok run on September 27, 2001. Methods: : Psychiatric inpatient admissions in the Canton of Zurich from September 2000 to September 2002 were analysed based on the data of the psychiatric case register. ARIMA modelling was employed to describe time-series of admissions per week over the 2-year period and to identify the impact of the incidents of 9/11 and 9/27,2001. Results: : Mean numbers of weekly admissions were comparable in a time span of one month before and one month after the two incidents, thus, no significant changes were detected by the ARIMA modelling. Conclusion: : Against widespread beliefs, for patients with severe mental disorders requiring hospitalisation illness factors seem to play a more relevant role for decompensation than external psychosocial factors such as the described incident

Observation of many-body long-range tunneling after a quantum quench

Quantum tunneling constitutes one of the most fundamental processes in nature. We observe resonantly-enhanced long-range quantum tunneling in one-dimensional Mott-insulating Hubbard chains that are suddenly quenched into a tilted configuration. Higher-order many-body tunneling processes occur over up to five lattice sites when the tilt per site is tuned to integer fractions of the Mott gap. Starting from a one-atom-per-site Mott state the response of the many-body quantum system is observed as resonances in the number of doubly occupied sites and in the emerging coherence in momentum space. Second- and third-order tunneling shows up in the transient response after the tilt, from which we extract the characteristic scaling in accordance with perturbation theory and numerical simulations.Comment: 22 pages, 7 figure

Preparation and spectroscopy of a metastable Mott insulator state with attractive interactions

We prepare and study a metastable attractive Mott insulator state formed with bosonic atoms in a three-dimensional optical lattice. Starting from a Mott insulator with Cs atoms at weak repulsive interactions, we use a magnetic Feshbach resonance to tune the interactions to large attractive values and produce a metastable state pinned by attractive interactions with a lifetime on the order of 10 seconds. We probe the (de-)excitation spectrum via lattice modulation spectroscopy, measuring the interaction dependence of two- and three-body bound state energies. As a result of increased on-site three-body loss we observe resonance broadening and suppression of tunneling processes that produce three-body occupation.Comment: 7 pages, 6 figure

Mental health literacy in an educational elite – an online survey among university students

BACKGROUND: Mental health literacy is a prerequisite for early recognition and intervention in mental disorders. The aims of this paper are to determine whether a sample of university students recognise different symptoms of depression and schizophrenia and to reveal factors influencing correct recognition. METHODS: Bivariate and correspondence analyses of the results from an online survey among university students (n = 225). RESULTS: Most participants recognised the specific symptoms of depression. The symptoms of schizophrenia were acknowledged to a lower extent. Delusions of control and hallucinations of taste were not identified as symptoms of schizophrenia. Repeated revival of a trauma for depression and split personality for schizophrenia were frequently mistaken as symptoms of the respective disorders. Bivariate analyses demonstrated that previous interest in and a side job related to mental disorders, as well as previous personal treatment experience had a positive influence on symptom recognition. The correspondence analysis showed that male students of natural science, economics and philosophy are illiterate in recognising the symptoms depression and schizophrenia. CONCLUSION: Among the educational elite, a wide variability in mental health literacy was found. Therefore, it's important for public mental health interventions to focus on the different recognition rates in depression and schizophrenia. Possibilities for contact must be arranged according to interest and activity (e.g., at work). In order to improve mental health literacy, finally, education and/or internship should be integrated in high school or apprenticeship curricula. Special emphasis must be given towards the effects of gender and stereotypes held about mental illnesses

Demonstration of the temporal matter-wave Talbot effect for trapped matter waves

We demonstrate the temporal Talbot effect for trapped matter waves using ultracold atoms in an optical lattice. We investigate the phase evolution of an array of essentially non-interacting matter waves and observe matter-wave collapse and revival in the form of a Talbot interference pattern. By using long expansion times, we image momentum space with sub-recoil resolution, allowing us to observe fractional Talbot fringes up to tenth order