Continuous-variable tomography of solitary electrons

Abstract: A method for characterising the wave-function of freely-propagating particles would provide a useful tool for developing quantum-information technologies with single electronic excitations. Previous continuous-variable quantum tomography techniques developed to analyse electronic excitations in the energy-time domain have been limited to energies close to the Fermi level. We show that a wide-band tomography of single-particle distributions is possible using energy-time filtering and that the Wigner representation of the mixed-state density matrix can be reconstructed for solitary electrons emitted by an on-demand single-electron source. These are highly localised distributions, isolated from the Fermi sea. While we cannot resolve the pure state Wigner function of our excitations due to classical fluctuations, we can partially resolve the chirp and squeezing of the Wigner function imposed by emission conditions and quantify the quantumness of the source. This tomography scheme, when implemented with sufficient experimental resolution, will enable quantum-limited measurements, providing information on electron coherence and entanglement at the individual particle level

Noncomparabilities & Non Standard Logics

Many normative theories set forth in the welfare economics, distributive justice and cognate literatures posit noncomparabilities or incommensurabilities between magnitudes of various kinds. In some cases these gaps are predicated on metaphysical claims, in others upon epistemic claims, and in still others upon political-moral claims. I show that in all such cases they are best given formal expression in nonstandard logics that reject bivalence, excluded middle, or both. I do so by reference to an illustrative case study: a contradiction known to beset John Rawls\u27s selection and characterization of primary goods as the proper distribuendum in any distributively just society. The contradiction is avoided only by reformulating Rawls\u27s claims in a nonstandard form, which form happens also to cohere quite attractively with Rawls\u27s intuitive argumentation on behalf of his claims

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Statelessness Determination in the Netherlands

The Netherlands lacks an adequate mechanism for the identification of stateless persons, and is therefore not complying with its international obligations in the field of statelessness. Contrary to the position of the Dutch government, the existing procedures that stateless persons can appeal to are not in conformity with the relevant international standards. This paper contains a detailed analysis of the two procedures which have been invoked by the Dutch government in defence of the current statelessness protection and identification regime in the Netherlands, namely the registration of individuals in population registers, and the procedure for obtaining the so-called ‘no-fault’ residence permit. It illustrates that neither of the two are effective alternatives for statelessness determination. In addition, recent legislative changes that might affect the registration of statelessness in the Netherlands are discussed, and a proposal put forward by the UNHCR for a determination procedure in courts is evaluated