Superconductivity in a chiral nanotube

Chirality of materials are known to affect optical, magnetic and electric properties, causing a variety of nontrivial phenomena such as circular dichiroism for chiral molecules, magnetic Skyrmions in chiral magnets and nonreciprocal carrier transport in chiral conductors. On the other hand, effect of chirality on superconducting transport has not been known. Here we report the nonreciprocity of superconductivity—unambiguous evidence of superconductivity reflecting chiral structure in which the forward and backward supercurrent flows are not equivalent because of inversion symmetry breaking. Such superconductivity is realized via ionic gating in individual chiral nanotubes of tungsten disulfide. The nonreciprocal signal is significantly enhanced in the superconducting state, being associated with unprecedented quantum Little-Parks oscillations originating from the interference of supercurrent along the circumference of the nanotube. The present results indicate that the nonreciprocity is a viable approach toward the superconductors with chiral or noncentrosymmetric structures

Immigrants and Refugees: From Social Disaffection to Perceived Threat

Immigrants and refugees are today represented as a threat by a significant number of Europeans and constitute a topic that divides Governments and is at the centre of the agenda of new European extreme right-wing. This chapter presents a new approach and innovative hypotheses about the factors underlying the representation of immigrants and refugees as a threat, and their role in legitimizing discrimination, social inequalities and the development of anti-immigrant and anti-refugee public policies. Our approach is based on the hypothesis that immigrants and refugees are perceived as a threat to individual and collective life projects, particularly by those experiencing a sense of social disaffection (i.e., a generalized feeling that conjointly expresses dissatisfaction with life, perception of lack of control over life and distrust of the social system’s nuclear institutions). Using new data from the European Social Survey, we propose an analytical model specifying the correlates of threat perceptions and the mediating role of threat on the relationship between social disaffection and opposition to immigration and refugees in Europe. Results have shown that the sense of threat is related to right-wing political positioning, exclusive national identity, anti-universalistic values and, more importantly, with the sense of social disaffection. Significantly, threat perceptions play a legitimating role in the relationship between social disaffection and opposition to immigration and to hosting refugees. We further discuss the theoretical and socio-political implications of our approach to the study of threat in the context of contemporary social dynamics.info:eu-repo/semantics/publishedVersio