Plasmon signatures in high harmonic generation

High harmonic generation in polarizable multi-electron systems is investigated in the framework of multi-configuration time-dependent Hartree-Fock. The harmonic spectra exhibit two cut offs. The first cut off is in agreement with the well established, single active electron cut off law. The second cut off presents a signature of multi-electron dynamics. The strong laser field excites non-linear plasmon oscillations. Electrons that are ionized from one of the multi-plasmon states and recombine to the ground state gain additional energy, thereby creating the second plateau.Comment: Major revision, 12 pages, 5 figures, submitted to J. Phys. B (2005), accepte

Antihumanism in queer theory

Although queer theory is distinguished by its antihumanistic rhetoric, in much of queer theory antihumanism is more about performance than substance. This is not a bad thing, for, on those occasions when queer theory takes its antihumanism too seriously, it commits itself to incoherence. I illustrate this through an intertextual critique of Edelman's and Bersani's works. Edelman's celebration of the death drive is internally torn between an amoral standpoint and immoral urges. Unlike recent critical interventions, however, my point is less to impugn queer theory's preoccupation with antinormativity, than the performance of antinormativity that manifests as queer antihumanism

Correlated non-perturbative electron dynamics with quantum trajectories

An approach to electron correlation effects in atoms that uses quantum trajectories is presented. A comparison with the exact quantum mechanical results for 1D Helium atom shows that the major features of the correlated ground state distribution and of the strong field ionization dynamics are reproduced with quantum trajectories. The intra-atomic resonant transitions are described accurately by a trajectory ensemble. The present approach reduces significantly the computational time and it can be used for both bound and ionizing electrons.Comment: 9 pages, 4 figure

Graceful remedies: understanding grace in the Catholic Church's treatment of clerical child sexual abuse

This article examines advocacy of Catholic restorative justice for clerical child sexual abuse from the standpoint of feminist criminological critiques of the use of restorative mediation in sexual offence cases. In particular, it questions the Catholic invocation of grace and forgiveness of survivors of abuse in light of critical feminist concerns about the exploitation of emotions in restorative practices, especially in regard to sexual and other gender-based offences. In the context of sexual abuse, the Catholic appeal to grace has the potential for turning into an extraordinary demand made of victims not only to rehabilitate offenders and the church in the eyes of the community, but also to work towards the spiritual absolution of the abuser. This unique feature of Catholic-oriented restorative justice raises important concerns in terms of feminist critiques of the risk of abuses of power within mediation, and is also incompatible with orthodox restorative justice theory, which, although it advocates a ‘spiritual’ response to crime, is concerned foremost with the rights, needs and experiences of victims

Phase Space Approach to Laser-driven Electronic Wavepacket Propagation

We propose a phase space method to propagate a quantum wavepacket driven by a strong external field. The method employs the so-called biorthogonal von Neumann basis recently introduced for the calculation of the energy eigenstates of time-independent quantum systems [A. Shimshovitz and D.J. Tannor, arXiv:1201.2299v1]. While the individual elements in this basis set are time-independent, a small subset is chosen in a time-dependent manner to adapt to the evolution of the wavepacket in phase space. We demonstrate the accuracy and efficiency of the present propagation method by calculating the electronic wavepacket in a one-dimensional soft-core atom interacting with a superposition of an intense, few-cycle, near-infrared laser pulse and an attosecond extreme-ultraviolet laser pulse.Comment: 4 pages, 4 figures. The following article has been submitted to the Journal of Chemical Physics. After it is published, it will be found at http://jcp.aip.org

Why rights are not optimisation requirements

In this article I pursue the implications of the statement that constitutional rights are – as Alexy’s principles theory argues – optimisation requirements, and show that they are not. I argue that, applied to moral rights, optimisation obfuscates their nature, their relationship to human well-being, and the work they do in practical thought. As to constitutional rights, I argue that the fact that they belong in an institutional framework suggests some reasons for treating them like optimisation requirements in circumscribed cases. But these reasons are far from conclusive; and treating rights like optimisation requirements in other scenarios (conflicts of rights, structural discretion) indicates that optimisation, as defined in the principles theory, does not assist us in thinking well about the structure of constitutional rights. Constitutional rights demand compliance with whatever the interests on which they are based demand – whether or not what they demand is antecedently clear – not with some purported optimisation requirement

Two Component Heat Diffusion Observed in CMR Manganites

We investigate the low-temperature electron, lattice, and spin dynamics of LaMnO_3 (LMO) and La_0.7Ca_0.3MnO_3 (LCMO) by resonant pump-probe reflectance spectroscopy. Probing the high-spin d-d transition as a function of time delay and probe energy, we compare the responses of the Mott insulator and the double-exchange metal to the photoexcitation. Attempts have previously been made to describe the sub-picosecond dynamics of CMR manganites in terms of a phenomenological three temperature model describing the energy transfer between the electron, lattice and spin subsystems followed by a comparatively slow exponential decay back to the ground state. However, conflicting results have been reported. Here we first show clear evidence of an additional component in the long term relaxation due to film-to-substrate heat diffusion and then develop a modified three temperature model that gives a consistent account for this feature. We confirm our interpretation by using it to deduce the bandgap in LMO. In addition we also model the non-thermal sub-picosecond dynamics, giving a full account of all observed transient features both in the insulating LMO and the metallic LCMO.Comment: 6 pages, 5 figures http://link.aps.org/doi/10.1103/PhysRevB.81.064434 v2: Abstract correcte

Frank's constant in the hexatic phase

Using video-microscopy data of a two-dimensional colloidal system the bond-order correlation function G6 is calculated and used to determine the temperature-dependence of both the orientational correlation length xi6 in the isotropic liquid phase and the Frank constant F_A in the hexatic phase. F_A takes the value 72/pi at the hexatic to isotropic liquid phase transition and diverges at the hexatic to crystal transition as predicted by the KTHNY-theory. This is a quantitative test of the mechanism of breaking the orientational symmetry by disclination unbinding