Boson Pairs in a One-dimensional Split Trap

We describe the properties of a pair of ultracold bosonic atoms in a one-dimensional harmonic trapping potential with a tunable zero-ranged barrier at the trap centre. The full characterisation of the ground state is done by calculating the reduced single-particle density, the momentum distribution and the two-particle entanglement. We derive several analytical expressions in the limit of infinite repulsion (Tonks-Girardeau limit) and extend the treatment to finite interparticle interactions by numerical solution. As pair interactions in double wells form a fundamental building block for many-body systems in periodic potentials, our results have implications for a wide range of problems.Comment: 9 pages, 8 figure

Putting Surveillance on the Political Agenda – A Short Defence of Surveillance: Citizens and the State

In February 2009 the House of Lords Constitutional Committee in the United Kingdom published the report Surveillance: Citizens and the State. Some have hailed this as a landmark document. Volume 6(3) of Surveillance & Society published 4 invited responses to this report written by prominent scholars. In the attached paper the two Specialist Advisers to this Committee set the context for the report and provide a brief rejoinder to the four responses. NOTE: The authors write in their academic and personal capacities, and not as representatives of the Committee

Association between health insurance literacy and avoidance of health care services owing to cost

Importance: Navigating health insurance and health care choices requires considerable health insurance literacy. Although recommended preventive services are exempt from out-of-pocket costs under the Affordable Care Act, many people may remain unaware of this provision and its effect on their required payment. Little is known about the association between individuals\u27 health insurance literacy and their use of preventive or nonpreventive health care services. Objective: To assess the association between health insurance literacy and self-reported avoidance of health care services owing to cost. Design, Setting, and Participants: In this survey study, a US national, geographically diverse, nonprobability sample of 506 US residents aged 18 years or older with current health insurance coverage was recruited to participate in an online survey between February 22 and 23, 2016. Main Outcomes and Measures: The validated 21-item Health Insurance Literacy Measure (HILM) assessed individuals\u27 self-rated confidence in selecting and using health insurance (score range, 0-84, with higher scores indicating greater levels of health insurance literacy). Dependent variables included delayed or foregone preventive and nonpreventive services in the past 12 months owing to perceived costs, and preventive and nonpreventive use of services. Covariates included age, sex, race/ethnicity, income, educational level, high-deductible health insurance plan, health literacy, numeracy, and chronic health conditions. Analyses included descriptive statistics and bivariate and multivariable logistic regression. Results: A total of 506 of 511 participants who began the survey completed it (participation rate, 99.0%). Of the 506 participants, 339 (67.0%) were younger than 35 years (mean [SD] age, 34 [10.4] years), 228 (45.1%) were women, 406 of 504 who reported race (80.6%) were white, and 245 (48.4%) attended college for 4 or more years. A total of 228 participants (45.1%) had 1 or more chronic health condition, 361 of 500 (72.2%) who responded to the survey item had seen a physician in the outpatient setting in the past 12 months, and 446 of the 501 (89.0%) who responded to the survey item had their health insurance plan for 12 or more months. One hundred fifty respondents (29.6%) reported having delayed or foregone care because of cost. The mean (SD) HILM score was 63.5 (12.3). In multivariable logistic regression, each 12-point increase in HILM score was associated with a lower likelihood of both delayed or foregone preventive care (adjusted odds ratio [aOR], 0.61; 95% CI, 0.48-0.78) and delayed or foregone nonpreventive care (aOR, 0.71; 95% CI, 0.55-0.91). Conclusions and Relevance: This study\u27s findings suggest that lower health insurance literacy may be associated with greater avoidance of both preventive and nonpreventive services. It appears that to improve appropriate use of recommended health care services, including preventive health services, clinicians, health plans, and policymakers may need to communicate health insurance concepts in accessible ways regardless of individuals\u27 health insurance literacy. Plain language communication may be able to improve patients\u27 understanding of services exempt from out-of-pocket costs

Solidarity and cost management: Swiss citizens’ reasons for priorities regarding health insurance coverage

ContextApproaches to priority‐setting for scarce resources have shifted to public deliberation as trade‐offs become more difficult. We report results of a qualitative analysis of public deliberation in Switzerland, a country with high health‐care costs, an individual health insurance mandate and a strong tradition of direct democracy with frequent votes related to health care.MethodsWe adapted the Choosing Healthplans All Together (CHAT) tool, an exercise developed to transform complex health‐care allocation decisions into easily understandable choices, for use in Switzerland. We conducted focus groups in twelve Swiss cities, recruiting from a range of socio‐economic backgrounds in the three language regions.FindingsParticipants developed strategic arguments based on the importance of basic coverage for all, and of cost‐benefit evaluation. They also expressed arguments relying on a principle of solidarity, in particular the importance of protection for vulnerable groups, and on the importance of medical care. They struggled with the place of personal responsibility in coverage decisions. In commenting on the exercise, participants found the degree of consensus despite differing opinions surprising and valuable.ConclusionThe Swiss population is particularly attentive to the costs of health care and means of reducing these costs. Swiss citizens are capable of making trade‐offs and setting priorities for complex health issues.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146495/1/hex12680.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146495/2/hex12680_am.pd

Quantum entanglement for systems of identical bosons: II. Spin squeezing and other entanglement tests

These two accompanying papers are concerned with entanglement for systems of identical massive bosons and the relationship to spin squeezing and other quantum correlation effects. The main focus is on two mode entanglement, but multi-mode entanglement is also considered. The bosons may be atoms or molecules as in cold quantum gases. The previous paper I dealt with the general features of quantum entanglement and its specific definition in the case of systems of identical bosons. Entanglement is a property shared between two (or more) quantum sub-systems. In defining entanglement for systems of identical massive particles, it was concluded that the single particle states or modes are the most appropriate choice for sub-systems that are distinguishable, that the general quantum states must comply both with the symmetrization principle and the super-selection rules (SSR) that forbid quantum superpositions of states with differing total particle number (global SSR compliance). Further, it was concluded that (in the separable states) quantum superpositions of sub-system states with differing sub-system particle number (local SSR compliance) also do not occur. The present paper II determines possible tests for entanglement based on the treatment of entanglement set out in paper I. Several inequalities involving variances and mean values of operators have been previously proposed as tests for entanglement between two sub-systems. These inequalities generally involve mode annihilation and creation operators and include the inequalities that define spin squeezing. In this paper, spin squeezing criteria for two mode systems are examined, and spin squeezing is also considered for principle spin operator components where the covariance matrix is diagonal. The proof, which is based on our SSR compliant approach shows that the presence of spin squeezing in any one of the spin components requires entanglement of the relevant pair of modes. A simple Bloch vector test for entanglement is also derived. Thus we show that spin squeezing becomes a rigorous test for entanglement in a system of massive bosons, when viewed as a test for entanglement between two modes. In addition, other previously proposed tests for entanglement involving spin operators are considered, including those based on the sum of the variances for two spin components. All of the tests are still valid when the present concept of entanglement based on the symmetrization and SSR criteria is applied. These tests also apply in cases of multi-mode entanglement, though with restrictions in the case of sub-systems each consisting of pairs of modes. Tests involving quantum correlation functions are also considered and for global SSR compliant states these are shown to be equivalent to tests involving spin operators. A new weak correlation test is derived for entanglement based on local SSR compliance for separable states, complementing the stronger correlation test obtained previously when this is ignored. The Bloch vector test is equivalent to one case of this weak correlation test. Quadrature squeezing for single modes is also examined but not found to yield a useful entanglement test, whereas two mode quadrature squeezing proves to be a valid entanglement test, though not as useful as the Bloch vector test. The various entanglement tests are considered for well-known entangled states, such as binomial states, relative phase eigenstates and NOON states—sometimes the new tests are satisfied while than those obtained in other papers are not. The present paper II then outlines the theory for a simple two mode interferometer showing that such an interferometer can be used to measure the mean values and covariance matrix for the spin operators involved in entanglement tests for the two mode bosonic system. The treatment is also generalized to cover multi-mode interferometry. The interferometer involves a pulsed classical field characterized by a phase variable and an area variable defined by the time integral of the field amplitude, and leads to a coupling between the two modes. For simplicity the center frequency was chosen to be resonant with the inter-mode transition frequency. Measuring the mean and variance of the population difference between the two modes for the output state of the interferometer for various choices of interferometer variables is shown to enable the mean values and covariance matrix for the spin operators for the input quantum state of the two mode system to be determined. The paper concludes with a discussion of several key experimental papers on spin squeezing

Lucky IP

A person naturally owns the fruits of their intellectual labour; so goes the labour argument for intellectual property. But what should happen when a creator gets ‘lucky’ – such as the photographer who is in the right place at the right time or the scientist who accidentally discovers a new drug? IP law frequently awards ownership in such cases (what we call ‘Lucky IP’). Some argue, however, that the creators in such cases do not labour sufficiently to deserve ownership, and that Lucky IP merely demonstrates that IP law is not truly concerned about labour at all. Drawing on the philosophical literature of moral luck, we argue that this analysis is misguided. Nearly all intellectual creations involve some measure of luck and, in most cases, the creators still labour sufficiently to become the natural owners of their creations. Lucky IP does not, therefore, undermine the labour theory of IP law

On Copyright Utilitarianism

Utilitarians typically argue that the state should grant copyright to authors only when doing so promotes utility. In recent years, however, this argument has faced three criticisms. As a normative matter, critics argue that a utilitarian copyright system is neither just nor attractive. As an epistemological matter, critics argue that society cannot ever know whether copyright promotes utility. And as an interpretive matter, critics argue that utilitarianism fails to appreciate what copyright is really all about: progress of the sciences and useful arts. And so, an increasing number of scholars conclude that copyright should be awarded, not when doing so aids utility, but when doing so secures natural rights or promotes democratic norms. This Article refines and defends the utilitarian argument for copyright law. The Article departs the company of prior utilitarians, however, in its conceptualization of “utility.” Taking inspiration from John Stuart Mill’s defense of utilitarianism, the Article argues that utility in copyright cannot be understood in purely quantitative terms. Of course, the overall amount of creative work that the copyright system generates matters a great deal; but it is not the only thing that matters. The type of creative work incentivized by the system also matters: creative work that feeds the mind, sparks feelings and imagination, and promotes moral sentiments provide copyright’s “higher pleasures.” A truly utilitarian copyright system is, therefore, one that produces more and better creative work. A utilitarian copyright of this kind is normatively attractive, epistemologically realistic, and interpretively consistent with the constitutional structure of American copyright law

Regulating CCTV? : We can't solve problems by using the same kind of thinking we used when we created them

Peer reviewedPostprin