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A method is presented for the incorporation of space‐charge effects into the analysis of one‐dimensional devices. At each bias, solutions of Schrödinger's and Poisson's equations are performed iteratively, until the solutions converge. Some difficulties in the calculation of electron density are noted, and an algorithm is described to insure an accurate computation. Finally, the current‐voltage characteristic of a recently fabricated resonant tunneling device is presented, to stress the importance of space‐charge effects.

With the advent of sophisticated growth techniques such as Molecular Beam Epitaxy and Metal Organic Chemical Vapor Deposition, the calculation of the energy boundstates and electron wave‐functions of the one‐electron Schrödinger equation has received a lot of attention over the last decade. With the more recent fabrication of quantum wires and dots, it seems now imperative to extend the boundstates calculation to systems containing only a few electrons. Hereafter, we investigate the effect of electron exchange and Coulomb interactions on the boundstates of a two‐electron system in a square quantum well. The technique is based on a general Alternating Direction Implicit algorithm ( T. Singh and M. Cahay, SPIE Vol. 1675, Quantum Wells and Superlattice Physics IV (1992), p.11) combined with a Fourier spectrum analysis of the two‐particle wavefunction correlation , <ψ(χ1,χ2;0)/ψ(χ1,χ2;τ)> , where χ1, χ2 are the coordinates of the two electrons. The precise location of the energy eigenvalues requires the appropriate use of window functions before calculating the Fourier transform of the correlation function. We also compare our results for the boundstate energies with those obtained using a first order time‐independent perturbation theory.

Various experimental groups have reported observation of both integer and fractional giant Shapiro steps in the I‐V curves of N×M arrays of superconducting‐normal metal‐superconducting (SNS) Josephson junctions. The size of these steps have been investigated both experimentally and theoretically as a function of temperature, external magnetic field, and rf current. In this report, we investigate the possibility of controlling the size of these giant Shapiro steps by an external gate voltage by considering arrays of superconductor‐semiconductor‐superconductor junctions. We show that giant Shapiro steps of different orders can be quenched over different gate voltage ranges in these arrays.

The paper aims to examine the environmental challenges of artificial intelligence (AI) in EU law that regard both illicit uses of the technology, i.e. overuse or misuse of AI and its possible underuses. The aim of the paper is to show how such regulatory efforts of legislators should be understood as a critical component of the Green Deal of the EU institutions, that is, to save our planet from impoverishment, plunder and destruction.

To illustrate the different ways in which AI can represent a game-changer for our environmental challenges, attention is drawn to a multidisciplinary approach, which includes the analysis of the initiatives on the European Green Deal; the proposals for a new legal framework on data governance and AI; principles of environmental and constitutional law; the interaction of such principles and provisions of environmental and constitutional law with AI regulations; other sources of EU law and of its Member States.

Most recent initiatives on AI, including the AI Act (AIA) of the European Commission, have insisted on a human-centric approach, whereas it seems obvious that the challenges of environmental law, including those triggered by AI, should be addressed in accordance with an ontocentric, rather than anthropocentric stance. The paper provides four recommendations for the legal consequences of this short-sighted view, including the lack of environmental concerns in the AIA.

The environmental challenges of AI suggest complementing current regulatory efforts of EU lawmakers with a new generation of eco-impact assessments; duties of care and disclosure of non-financial information; clearer parameters for the implementation of the integration principle in EU constitutional law; special policies for the risk of underusing AI for environmental purposes. Further research should examine these policies in connection with the principle of sustainability and the EU plan for a circular economy, as another crucial ingredient of the Green Deal.

The paper provides a set of concrete measures to properly tackle both illicit uses of AI and the risk of its possible underuse for environmental purposes. Such measures do not only concern the “top down” efforts of legislators but also litigation and the role of courts. Current trends of climate change litigation and the transplant of class actions into several civil law jurisdictions shed new light on the ways in which we should address the environmental challenges of AI, even before a court.

A more robust protection of people’s right to a high level of environmental protection and the improvement of the quality of the environment follows as a result of the analysis on the legal threats and opportunities brought forth by AI.

The paper explores a set of issues, often overlooked by scholars and institutions, that is nonetheless crucial for any Green Deal, such as the distinction between the human-centric approach of current proposals in the field of technological regulation and the traditional ontocentric stance of environmental law. The analysis considers for the first time the legal issues that follow this distinction in the field of AI regulation and how we should address them.

This exploratory study uses a punctuated equilibrium paradigm (PEP) framework to examine the impact and adaptation of an entrepreneurial ecosystem (EE) to the COVID-19 pandemic at the organizational and ecosystem level. The aim is to provide guidance to EEs on ways to adapt to future external shocks.

As this study is exploratory in nature, the authors use a sequential mixed method whereby a qualitative method is used first to identify emergent themes from in-depth interviews with EE members, followed by a quantitative method (survey) based on those themes across a broader cross section of EE members.

Entrepreneurial ecosystem’s geographical advantages have declined during the pandemic as EE firms adapted to this external shock by developing more digitally distributed organizations.

Based on the findings, the authors propose an emerging model of EEs that extends the traditional clustering model focused on geography to account for more digitally distributed entrepreneurial clusters. However, the results, based on an in-depth study of one ecosystem, may not be fully generalizable to all EEs.

Given the widespread pandemic impact, the findings may be instructive to EEs and organizations in EEs that aim to become more resilient in the face of potential future external shocks.

As part of the qualitative interview process the interviewees were asked what they would change in San Francisco Bay Area if they had a magic wand right now. They discussed a variety of inspiring ideas, but the most frequently mentioned was their wish to change the focus of business to solve societal problems with a global citizen mindset (e.g. recycling energy, climate change, income inequality, access to education and funding, inequity, wealth gaps, housing crisis and homelessness) to make the world a better place. Additionally, the pandemic exposed some inequality in work conditions across demographics. As firms reorganize to increase resiliency, attention to these issues should be addressed.

This study is unique in applying the PEP to EEs to deepen our understanding about how an EE evolves during periods of sudden external shocks.