Quantum estimation and remote charge sensing with a hole-spin qubit in silicon

Hole-spin qubits in semiconductors represent a mature platform for quantum technological applications. Here we consider their use as quantum sensors, and specifically for inferring the presence and estimating the distance from the qubit of a remote charge. Different approaches are considered, based on the use of single or double quantum dots, ground and out-of-equilibrium states, Rabi and Ramsey measurements, and comparatively analyzed by means of the discrimination probability, and of the classical and quantum Fisher information. Detailed quantitative aspects result from the multiband character of the hole states, which we account for by means of the Luttinger-Kohn Hamiltonian. Furthermore, general conclusions can be drawn on the relative efficiency of the above options, and analytical expressions are derived for the Fisher information of a generic qubit within the Rabi and Ramsey schemes

Histoires et quartiers. Méthodes, narrations, acteurs

In recent years, the history of neighborhoods has attracted a renewed interest with regard to urban policy investigations and their qualitative objectives, thus experiencing a return to human scale, to proximity, and to the “15-minute city.” A resurgence of historical engagement occurs from various directions and within different domains, such as habitat and housing, neighborhood facilities, employment, mobility, and neighbor relations. These new perspectives question several scales (local, national, transnational, global) by seeing neighborhoods as places where construction practices and spatial representation intersect at different levels. This issue on “Histories and neighborhoods” develops along the lines of two approaches: methodological and epistemological aspects, as well as research strategies (1), and the construction and uses of narratives with actors in specific urban contexts (2). It is interested in the ways in which these questions are addressed in different political contexts and scientific milieux. Over the past ten years, in the fields of urban history, architecture and landscape, and in urban sectors more specifically, we have witnessed attempts at interdisciplinary hybridization between research practices, methodologies and tools that come from different disciplinary backgrounds: archival research, ethnography, history written by public institutions, oral history, and field observations. These methodological dialogues go beyond cleavages between quantitative and qualitative research, subjective or objective observation, micro and macro-history, or architectural typology and uses of space. Indeed, these research approaches make it possible to develop interplays of scale, from the micro to the macro, from a domestic setting to the territory, and from everyday actors to structural, institutional or even political actors. Which research strategies are at work? What types of narratives do they produce? How does opening up to the field of representations and identities of local groups integrate social interactions into the analysis of spatial and structural logics? In addition to interview excerpts, as well as graphic, audible and pictorial documents, what types of materials are used? Finally, to what extent is architectural, urban and landscape research well positioned to develop new forms of methodological hybridization? These approaches also lead to different cross-referencing of research topics, and to multiple definitions of the notion of “neighborhood,” the implications of which are explored in this issue. Neighborhood histories can also be perceived as the result of a negotiation in which historians find themselves coproducing interpretations within the framework of a dialogue with narratives developed on different stages, particularly political ones, and carried out by actors with varied objectives and forms of communication. The issue questions the positioning of research as it faces an abundance of diachronic narratives already layered on neighborhoods, part of which do not circulate in academic literature, but rather through forms of oral or written transmission conveyed by political, administrative, professional, associative, and resident networks, etc. We will also focus on the “demand for history”, from the part of planners and other social groups, and on the need to develop historical accounts capable of addressing the questions about the transformation of space, but also on the risk of producing timeless, fictitious or “presentist” spaces. From this perspective, we can question historical research integrating a participatory research methodology and assembling non-academic forms of narration and representation. This will raise questions relating to the coordination of narratives and memories, the contribution of testimonies to the archive and, more broadly, the layering of narratives. In this framework, and in the face of memorial and heritage groups and their tools, the contribution of the architect, urban planner or landscape architect is approached in the production of a common or consolidated history, or even of history as a common good, simultaneously capable of integrating a plurality of perspectives, even potentially conflicting ones. Without revisiting debates on the notion of neighborhood, already thoroughly addressed in the social sciences, and without seeking to establish a universal definition, the issue questions the way in which historiography takes hold of this notion. As such, the diversity of case studies makes it possible to understand how the historical narrative captures the scales of the “neighborhood” in different contexts

Can stochastic resonance explain recurrence of Grand Minima?

The amplitude of the 11 yr solar cycle is well known to be subject to long-term modulation, including sustained periods of very low activity known as Grand Minima. Stable long-period cycles found in proxies of solar activity have given new momentum to the debate about a possible influence of the tiny planetary tidal forcing. Here, we study the solar cycle by means of a simple zero-dimensional dynamo model, which includes a delay caused by meridional circulation as well as a quenching of the α-effect at toroidal magnetic fields exceeding an upper threshold. Fitting this model to the sunspot record, we find a set of parameters close to the bifurcation point at which two stable oscillatory modes emerge. One mode is a limit cycle resembling normal solar activity including a characteristic kink in the decaying limb of the cycle. The other mode is a weak sub-threshold cycle that could be interpreted as Grand Minimum activity. Adding noise to the model, we show that it exhibits Stochastic Resonance, which means that a weak external modulation can toss the dynamo back and forth between these two modes, whereby the periodicities of the modulation get strongly amplified

Why lithium should be used in patients with bipolar disorder? A scoping review and an expert opinion paper

Introduction: Lithium treatment is considered the gold standard for the long-term management of bipolar disorder and recurrent unipolar depression. It is also extremely effective in other psychiatric conditions characterized by impulsivity and aggression, and for the prevention of suicidal behaviours. Areas covered: This paper provides a scoping review and an expert commentary regarding the use of lithium in adult patients. Available information about efficacy, tolerability, dosing, and switching is analyzed, and the strategies that may be most useful in real-world clinical settings are highlighted. Expert opinion: Lithium is effective on different domains of bipolar disorder, including the long-term prevention of recurrences of affective episodes, management of acute mania as well as in the prophylaxis of all affective episodes. Lithium has been defined a 'forgotten drug,' since its use in routine clinical practice has been declined over the last 20 or 30 years. Reasons for this trend include lack of adequate training on the management of lithium side effects. Considering its efficacy, use of lithium in ordinary clinical practice should be promoted. Several strategies, such as using slow-release formulations, can be easily implemented in order to minimize lithium side effects and improve its tolerability profile

Towards a definition of a real-time forecasting network for rainfall induced shallow landslides

PREVIEW is an European Commission FP6 Integrated Project with the aim of developing, at an European level, innovative geo-information services for atmospheric, geophysical and man-made risks. Within this framework, the Landslides Platform Service 2 (forecasting of shallow rapid slope movements) has developed an integrated procedure for the forecasting and warning of distributed shallow landsliding to be used for civil protection purposes. The Service consists of an automated end-to-end forecasting chain which uses data from a probabilistic downscaled short-term rainfall forecast, soil saturation estimates and meteorological radar outputs. The above data are entered into a hydro-geological model that makes use of an infinite slope approach to calculate the distributed Factor of Safety over the entire basin. All outputs, and much of the input data, are shown on a WebGIS system so that end-users can interactively access and download data. A distinctive feature of the service is the use of an innovative soil depth model for predicting the distributed thickness of the regolith cover within the basin, which is one of the most important parameters controlling shallow landslide triggering. The service was developed in a pilot test site in NE Italy, the Armea basin. Validation makes use of two rainfall events: one that occurred in 2000 and a smaller, more recent event (2006) that caused fewer landslides. Rainfall data have been used to compute a distributed factor-of-safety map that has been overlaid onto the landslide inventory. Instead of a traditional validation approach based on the number count of correctly identified landslides, we carried out an alternative procedure based on the landslides area that gave outcomes which, for this preliminary stage of the research, can be considered promising

La mappatura dei modelli digitali ottenuti mediante sensori attivi: verso nuove e più ampie prospettive di utilizzo

Il problema della mappatura del colore sui modelli digitali 3D ottenuti da sensori attivi apre numerose opportunità di ricerca e di riflessione dal momento in cui gli attuali sistemi di rilevamento laser scanner presentano limitazioni circa l’acquisizione del colore apparente, sia dovute alle condizioni logistiche del rilevamento, sia imputabili alle caratteristiche delle fotocamere montate su tali apparecchi. Il caso di studio qui trattato riguarda il progetto pilota per la valorizzazione e la salvaguardia delle chiese barocche in stile Ispano-americano facenti parte del patrimonio architettonico della città di Antigua Guatemala (Guatemala) fortemente danneggiato nel corso del secolo XVIII da un sisma di grande entità. L’obiettivo del progetto è quello di costruire modelli digitali 3D in grado di rappresentare accuratamente l’attuale stato di conservazione delle strutture e delle superfici esterne che presentano in molti casi un ricco apparato decorativo caratterizzato da affreschi policromi. Il rilevamento della Chiesa della Compagnia di Gesù eseguito attraverso scanner laser a variazione di fase non è però in grado di produrre texture del colore apparente a risoluzioni sufficientemente alte ed in condizioni favorevoli da consentire una adeguata mappatura sotto il profilo radiometrico; pertanto si è provveduto ad eseguire una apposita campagna fotografica finalizzata all’ottenimento di mappe di alta qualità corrette grazie a strumenti di editing bitmap che fanno largo uso dei vantaggi tipici dei formati .HDR e .RAW. Le texture del colore, integrate da mappe di normali e di scostamento, hanno permesso di realizzare modelli ottimizzati e multifunzione capaci cioè di fornire rappresentazioni interattive di alta qualità (fruibili via web attraverso applicazioni real-time), così come elaborati finalizzati alle pratiche di manutenzione e restauro attraverso disegni 2D. Il binomio costituito dalla sinergia di applicativi fotogrammetrici e di editing evoluto di immagini a 32 bit conferisce alla mappatura dei modelli digitali una affidabilità ad ampio raggio, tale da renderli congrui con le più elevate esigenze di conservazione e diffusione