Protecting the past for the public good: archaeology and Australian heritage law

Archaeological remains have long been recognised as fragile evidence of the past, which require protection. Legal protection for archaeological heritage has existed in Australia for more than thirty years but there has been little analysis of the aims and effectiveness of that legislation by the archaeological profession. Much Australian heritage legislation was developed in a period where the dominant paradigm in archaeological theory and practice held that archaeology was an objective science. Australian legislative frameworks continue to strongly reflect this scientific paradigm and contemporary archaeological heritage management practice is in turn driven by these legislative requirements. This thesis examines whether archaeological heritage legislation is fulfilling its original intent. Analysis of legislative development in this thesis reveals that legislators viewed archaeological heritage as having a wide societal value, not solely or principally for the archaeological community. Archaeological heritage protection is considered within the broader philosophy of environmental conservation. As an environmental issue, it is suggested that a ‘public good’ conservation paradigm is closer to the original intent of archaeological heritage legislation, rather than the “scientific” paradigm which underlies much Australian legislation. Through investigation of the developmental history of Australian heritage legislation it is possible to observe how current practice has diverged from the original intent of the legislation, with New South Wales and Victoria serving as case studies. Further analysis is undertaken of the limited number of Australian court cases which have involved substantial archaeological issues to determine the court’s attitude to archaeological heritage protection. Situating archaeological heritage protective legislation within the field of environmental law allows the examination of alternate modes of protecting archaeological heritage and creates opportunities for ‘public good’ conservation outcomes. This shift of focus to ‘public good’ conservation as an alternative to narrowly-conceived scientific outcomes better aligns with current public policy directions including the sustainability principles, as they have developed in Australia, as well as indigenous rights of self-determination. The thesis suggests areas for legal reforms which direct future archaeological heritage management practice to consider the ‘public good’ values for archaeological heritage protection

Nonquasiparticle states in the half-metallic ferromagnet NiMnSb

Nonquasiparticle states above the Fermi energy are studied by first-principle dynamical mean field calculations for a prototype half-metallic ferromagnet, NiMnSb. We present a quantitative evaluation of the spectral weight of this characteristic feature and discuss the possible experimental investigation (BIS, NMR, STM and Andreev reflection) to clarify the existence of these states.Comment: 15 pages, 4 figures, acepted in PR

Theory of Doping: Monovalent Adsorbates

Contains fulltext : 224022.pdf (Publisher’s version ) (Open Access

First- principle calculations of magnetic interactions in correlated systems

We present a novel approach to calculate the effective exchange interaction parameters based on the realistic electronic structure of correlated magnetic crystals in local approach with the frequency dependent self energy. The analog of ``local force theorem'' in the density functional theory is proven for highly correlated systems. The expressions for effective exchange parameters, Dzialoshinskii- Moriya interaction, and magnetic anisotropy are derived. The first-principle calculations of magnetic excitation spectrum for ferromagnetic iron, with the local correlation effects from the numerically exact QMC-scheme is presented.Comment: 17 pages, 3 Postscript figure

A note on cluster methods for strongly correlated electron systems

We develop, clarify and test various aspects of cluster methods dynamical mean field methods using a soluble toy model as a benchmark. We find that the Cellular Dynamical Mean Field Theory (C-DMFT) converges very rapidly and compare its convergence properties with those of the Dynamical Cluster Approximation (DCA). We propose and test improved estimators for the lattice self energy within C-DMFT.Comment: 5 pages, 3 figures; major change

Demonstration of a quantum nondemolition sum gate

The sum gate is the canonical two-mode gate for universal quantum computation based on continuous quantum variables. It represents the natural analogue to a qubit C-NOT gate. In addition, the continuous-variable gate describes a quantum nondemolition (QND) interaction between the quadrature components of two light fields. We experimentally demonstrate a QND sum gate, employing the scheme by R. Filip, P. Marek, and U.L. Andersen [\pra {\bf 71}, 042308 (2005)], solely based on offline squeezed states, homodyne measurements, and feedforward. The results are verified by simultaneously satisfying the criteria for QND measurements in both conjugate quadratures.Comment: 4 pages, 4 figure

Dual boson approach to collective excitations in correlated fermionic systems

We develop a general theory of a boson decomposition for both local and non-local interactions in lattice fermion models which allows us to describe fermionic degrees of freedom and collective charge and spin excitations on equal footing. An efficient perturbation theory in the interaction of the fermionic and the bosonic degrees of freedom is constructed in so-called dual variables in the path-integral formalism. This theory takes into account all local correlations of fermions and collective bosonic modes and interpolates between itinerant and localized regimes of electrons in solids. The zero-order approximation of this theory corresponds to extended dynamical mean-field theory (EDMFT), a regular way to calculate nonlocal corrections to EDMFT is provided. It is shown that dual ladder summation gives a conserving approximation beyond EDMFT. The method is especially suitable for consideration of collective magnetic and charge excitations and allows to calculate their renormalization with respect to "bare" RPA-like characteristics. General expression for the plasmonic dispersion in correlated media is obtained. As an illustration it is shown that effective superexchange interactions in the half-filled Hubbard model can be derived within the dual-ladder approximation.Comment: Extended version, 17 pages, 5 figure

Correlated Electrons Step-by-Step: Itinerant-to-Localized Transition of Fe Impurities in Free-Electron Metal Hosts

High-resolution photoemission spectroscopy and realistic ab-initio calculations have been employed to analyze the onset and progression of d-sp hybridization in Fe impurities deposited on alkali metal films. The interplay between delocalization, mediated by the free-electron environment, and Coulomb interaction among d-electrons gives rise to complex electronic configurations. The multiplet structure of a single Fe atom evolves and gradually dissolves into a quasiparticle peak near the Fermi level with increasing the host electron density. The effective multi-orbital impurity problem within the exact diagonalization scheme describes the whole range of hybridizations.Comment: 10 pages, 4 figure

Effect of local Coulomb interactions on the electronic structure and exchange interactions in Mn12 magnetic molecules

We have studied the effect of local Coulomb interactions on the electronic structure of the molecular magnet Mn12-acetate within the LDA+U approach. The account of the on-site repulsion results in a finite energy gap and an integer value of the molecule's magnetic moment, both quantities being in a good agreement with the experimental results. The resulting magnetic moments and charge states of non-equivalent manganese ions agree very well with experiments. The calculated values of the intramolecular exchange parameters depend on the molecule's spin configuration, differing by 25-30% between the ferrimagnetic ground state and the completely ferromagnetic configurations. The values of the ground-state exchange coupling parameters are in reasonable agreement with the recent data on the magnetization jumps in megagauss magnetic fields. Simple estimates show that the obtained exchange parameters can be applied, at least qualitatively, to the description of the spin excitations in Mn12-acetate.Comment: RevTeX, LaTeX2e, 4 EPS figure

Strong-coupling d-wave superconductivity in PuCoGa5 probed by point-contact spectroscopy

Superconductivity is due to an attractive interaction between electrons that, below a critical temperature, drives them to form Cooper pairs and to condense into a ground state separated by an energy gap from the unpaired states. In the simplest cases, the pairing is mediated by lattice vibrations and the wavefunction of the pairs is isotropic. Less conventional pairing mechanisms can favour more exotic symmetries of the Cooper pairs. Here, we report on point-contact spectroscopy measurements in PuCoGa5, a moderate heavy-fermion superconductor with a record high critical temperature Tc=18.5 K. The results prove that the wavefunction of the paired electrons has a d-wave symmetry, with four lobes and nodes, and show that the pairing is likely to be mediated by spin fluctuations. Electronic structure calculations, which take into account the full structure of the f-orbital multiplets of Pu, provide a hint of the possible origin of these fluctuations