Resonant tunneling controlled by laser and constant electric fields

We develop the concept of scattering matrix and we use it to perform stable numerical calculations of resonant tunneling of electrons through a multiple potential barrier in a semiconductor heterostructure. Electrons move in two external nonperturbative electric fields: constant and oscillating in time. We apply our algorithm for different strengths and spatial configurations of the fields.Comment: 10 pages, 11 figure

A revision of the Lower Cretaceous foraminiferal genus Falsogaudryinella from northwest Europe and Romania, and its relationship to Uvigerinammina

We emend the definition of the foraminiferal genus Falsogaudryinella Bartenstein, 1977 based on observations of the type species, F. tealbyensis from the Barremian Lower Tealby Clay of Lincolnshire, U.K. The genus was described by Loeblich & Tappan (1987) as having initial triserial coiling which reduces to biserial and finally uniserial. However, topotype specimens display high trochospiral coiling in the microsphaeric generation, with at least four chambers in the initial whorl. The genus, therefore, does not belong in the family Verneuilinidae, but must be transferred to the Prolixoplectidae. The wall is solid, non-canaliculate. The connections between chambers are in the form of tubes that extend from the basal part of the chamber lumina toward a terminal aperture. This tubular connection is partially separated from the main part of the chamber lumina by a septum. The presence of this tubular connection in F. tealbyensis is closely analogous to that observed in the type species of Uvigerinammina Majzon, 1943. The two genera, therefore, are separated mainly on the basis of cement type, with Falsogaudryinella possessing calcareous cement and Uvigerinammina organic cement. We illustrate five species of Falsogaudryinella from the Barremian of Lincolnshire, the U.K. sector of the Central North Sea, and from the Barremian and the Albian of Romania (F. neagui Bartenstein, 1981, F. praemoesiana n.sp. F. tealbyensis (Bartenstein, 1956), F. xenogena n.sp. and F. moesiana (Neagu, 1966)). Our investigations reveal that upper Hauterivian to Barremian specimens from the North Sea that have been previously regarded as F. moesiana (e.g. King et al., 1989) in fact belong in a new species, Falsogaudryinella praemoesiana n.sp. A second new species, Falsogaudryinella xenogena n.sp. is described from the Barremian of the Central North Sea. Evolution within the mid- Cretaceous Falsogaudryinella group appears to progress by reduction of the terminal uniserial part, since the coiling in the stratigraphically youngest form (F. moesiana) is predominantly triserial. Our interpretations of the phylogeny of the Cretaceous Falsogaudryinella and Uvigerinammina lineages are presented

Catalyzing Privacy Law

The United States famously lacks a comprehensive federal data privacy law. In the past year, however, over half the states have proposed broad privacy bills or have established task forces to propose possible privacy legislation. Meanwhile, congressional committees are holding hearings on multiple privacy bills. What is catalyzing this legislative momentum? Some believe that Europe’s General Data Protection Regulation (GDPR), which came into force in 2018, is the driving factor. But with the California Consumer Privacy Act (CCPA) which took effect in January 2020, California has emerged as an alternate contender in the race to set the new standard for privacy.Our close comparison of the GDPR and California’s privacy law reveals that the California law is not GDPR-lite: it retains a fundamentally American approach to information privacy. Reviewing the literature on regulatory competition, we argue that California, not Brussels, is catalyzing privacy law across the United States. And what is happening is not a simple story of powerful state actors. It is more accurately characterized as the result of individual networked norm entrepreneurs, influenced and even empowered by data globalization. Our study helps explain the puzzle of why Europe’s data privacy approach failed to spur US legislation for over two decades. Finally, our study answers critical questions of practical interest to individuals—who will protect my privacy?—and to businesses—whose rules should I follow

How to make semiconductors ferromagnetic: A first course on spintronics

The rapidly developing field of ferromagnetism in diluted magnetic semiconductors, where a semiconductor host is magnetically doped by transition metal impurities to produce a ferromagnetic semiconductor (e.g. Ga_{1-x}Mn_xAs with x ~ 1-10 %), is discussed with the emphasis on elucidating the physical mechanisms underlying the magnetic properties. Recent key developments are summarized with critical discussions of the roles of disorder, localization, band structure, defects, and the choice of materials in producing good magnetic quality and high Curie temperature. The correlation between magnetic and transport properties is argued to be a crucial ingredient in developing a full understanding of the properties of ferromagnetic semiconductors.Comment: 8 pages; to appear in the special issue 'Quantum Phases at Nanoscale' of Solid State Communication

Response of deep-water agglutinated foraminifera to dysoxic conditions in the California Borderland basins

Analysis of agglutinated benthic foraminifera from surface samples collected in the San Pedro and Santa Catalina Basins reveals a predictable relationship between the proportions of morphogroups with decreasing bottom water oxygen levels and with the TOC content of the surficial sediment. Living (Rose Bengal stained) foraminiferal faunas from dysaerobic environments display low diversity and high dominance, suggesting stressed conditions. There is an inverse relationship between oxygen and the relative abundance of deep infaunal morphogroups. Samples collected from shallow stations above the oxygen minimum zone are comprised of epifaunal and shallow infaunal morphotypes. At intermediate depths (~500 m), there is a peak in the abundance of suspension-feeding and "climbing" forms (watchglass-shaped trochamminids attached to Rhabdammina). Specimens from intermediate stations display the largest overall size. Deeper in the San Pedro Basin the living fauna is dominated by a small, flattened, tapered, species that is interpreted as having a deep infaunal microhabitat. In the dysaerobic environments off California the greatest degree of faunal change occurs when bottom water dissolved oxygen values drop from 0.5 ml/l to 0.2 ml/l. The effect of TOC content on the benthic fauna is demonstrated at two stations from the same depth in the San Pedro Basin. The station with the higher TOC content (4.2% vs. 2.9%) contains greater proportions of the small, deep infaunal morphotype. These faunal changes may be attributed to differences in the depth of the oxygenated zone within the sediment surface layer. Agglutinated faunas from areas that experience seasonal anoxia are comprised of a large proportion of opportunistic forms such as Reophax and Psammosphaera. These are the same taxa that colonised abiotic sediment trays in a recolonisation experiment in the Panama Basin. This study further demonstrates that agglutinated foraminiferal morphotypes respond in a similar manner to calcareous benthic foraminifera in dysaerobic environments

When the Default Is No Penalty: Negotiating Privacy at the NTIA

Consumer privacy protection is largely within the purview of the Federal Trade Commission. In recent years, however, the National Telecommunications and Information Administration (NTIA) at the Department of Commerce has hosted multistakeholder negotiations on consumer privacy issues. The NTIA process has addressed mobile apps, facial recognition, and most recently, drones. It is meant to serve as a venue for industry self-regulation. Drawing on the literature on co-regulation and on penalty defaults, I suggest that the NTIA process struggles to successfully extract industry expertise and participation against a dearth of federal data privacy law and enforcement. This problem is most exacerbated in precisely the areas the NTIA currently addresses: consumer privacy protection around new technologies and practices. In fact, industry may be more likely to see the NTIA process as itself penalty-producing and, thus, be disincentivized from meaningful participation or adoption

The Right to Explanation, Explained

Many have called for algorithmic accountability: laws governing decision-making by complex algorithms, or AI. The EU’s General Data Protection Regulation (GDPR) now establishes exactly this. The recent debate over the right to explanation (a right to information about individual decisions made by algorithms) has obscured the significant algorithmic accountability regime established by the GDPR. The GDPR’s provisions on algorithmic accountability, which include a right to explanation, have the potential to be broader, stronger, and deeper than the preceding requirements of the Data Protection Directive. This Essay clarifies, largely for a U.S. audience, what the GDPR actually requires, incorporating recently released authoritative guidelines

Binary Governance: Lessons from the GDPR’s Approach to Algorithmic Accountability

Algorithms are now used to make significant decisions about individuals, from credit determinations to hiring and firing. But they are largely unregulated under U.S. law. A quickly growing literature has split on how to address algorithmic decision-making, with individual rights and accountability to nonexpert stakeholders and to the public at the crux of the debate. In this Article, I make the case for why both individual rights and public- and stakeholder-facing accountability are not just goods in and of themselves but crucial components of effective governance. Only individual rights can fully address dignitary and justificatory concerns behind calls for regulating algorithmic decision-making. And without some form of public and stakeholder accountability, collaborative public-private approaches to systemic governance of algorithms will fail. In this Article, I identify three categories of concern behind calls for regulating algorithmic decision-making: dignitary, justificatory, and instrumental. Dignitary concerns lead to proposals that we regulate algorithms to protect human dignity and autonomy; justificatory concerns caution that we must assess the legitimacy of algorithmic reasoning; and instrumental concerns lead to calls for regulation to prevent consequent problems such as error and bias. No one regulatory approach can effectively address all three. I therefore propose a two-pronged approach to algorithmic governance: a system of individual due process rights combined with systemic regulation achieved through collaborative governance (the use of private-public partnerships). Only through this binary approach can we effectively address all three concerns raised by algorithmic decision-making, or decision-making by Artificial Intelligence (“AI”). The interplay between the two approaches will be complex. Sometimes the two systems will be complementary, and at other times, they will be in tension. The European Union’s (“EU’s”) General Data Protection Regulation (“GDPR”) is one such binary system. I explore the extensive collaborative governance aspects of the GDPR and how they interact with its individual rights regime. Understanding the GDPR in this way both illuminates its strengths and weaknesses and provides a model for how to construct a better governance regime for accountable algorithmic, or AI, decision-making. It shows, too, that in the absence of public and stakeholder accountability, individual rights can have a significant role to play in establishing the legitimacy of a collaborative regime

Binary Governance: Lessons from the GDPR’s Approach to Algorithmic Accountability

Algorithms are now used to make significant decisions about individuals, from credit determinations to hiring and firing. But they are largely unregulated under U.S. law. A quickly growing literature has split on how to address algorithmic decision-making, with individual rights and accountability to nonexpert stakeholders and to the public at the crux of the debate. In this Article, I make the case for why both individual rights and public- and stakeholder-facing accountability are not just goods in and of themselves but crucial components of effective governance. Only individual rights can fully address dignitary and justificatory concerns behind calls for regulating algorithmic decision-making. And without some form of public and stakeholder accountability, collaborative public-private approaches to systemic governance of algorithms will fail. In this Article, I identify three categories of concern behind calls for regulating algorithmic decision-making: dignitary, justificatory, and instrumental. Dignitary concerns lead to proposals that we regulate algorithms to protect human dignity and autonomy; justificatory concerns caution that we must assess the legitimacy of algorithmic reasoning; and instrumental concerns lead to calls for regulation to prevent consequent problems such as error and bias. No one regulatory approach can effectively address all three. I therefore propose a two-pronged approach to algorithmic governance: a system of individual due process rights combined with systemic regulation achieved through collaborative governance (the use of private-public partnerships). Only through this binary approach can we effectively address all three concerns raised by algorithmic decision-making, or decision-making by Artificial Intelligence (“AI”). The interplay between the two approaches will be complex. Sometimes the two systems will be complementary, and at other times, they will be in tension. The European Union’s (“EU’s”) General Data Protection Regulation (“GDPR”) is one such binary system. I explore the extensive collaborative governance aspects of the GDPR and how they interact with its individual rights regime. Understanding the GDPR in this way both illuminates its strengths and weaknesses and provides a model for how to construct a better governance regime for accountable algorithmic, or AI, decision-making. It shows, too, that in the absence of public and stakeholder accountability, individual rights can have a significant role to play in establishing the legitimacy of a collaborative regime