News / Highlights / Colloquia
- Published on 10 November 2010
A Colloquium paper by McEniry et al. published in EPJ B surveys the theory and applications of a new family of computational methods, namely Correlated Electron-Ion Dynamics, which enable the simultaneous evaluation of the electronic current, along with the current-induced forces and subsequent motion of the nuclei.
- Published on 18 October 2010
Members of the European Physical Societies represented in the EPJ Scientific Advisory Committee who choose to publish their EPJ paper in open access enjoy a 10% discount on the open access fee. For detailed information on how open access works in EPJ please click here.
- Published on 01 October 2010
Ground breaking experiments in EPJ B by D. Honecker and colleagues on an FeCr two-phase nanocrystalline alloy demonstrate the power of one-dimensional neutron-spin analysis in a small-angle neutron scattering (SANS) experiment.
- Published on 14 September 2010
New experiments on the flow of solid He through a microscopic hole reveal a mechanism that triggers the geysers based on the breakdown of a plug located upstream of the source chamber.
The vacuum expansion of solid helium through a micrometric orifice was suggested as a mean to inject excess vacancies into the solid bulk [R. Grisenti et al, J. Electr. Spectr. 129 (2003) 201]. But while the He flow seems smooth, unexpected periodic bursts out of the orifice (geyser effect) are observed during these vacuum expansion experiments.
- Published on 11 June 2010
Only one liquid exhibits Bose-Einstein condensation in nature: Helium II, . At such temperatures, all other substances are solid. In these two papers, Vitaly Golovko demonstrates that Bose-Einstein condensation can also occur in the solid state. Moreover, it is shown that at 0 K, a condensate crystal is energetically preferable with respect to the same quantum crystal without condensate. Therefore, on lowering the temperature of the crystal there must somewhere happen Bose-Einstein condensation, as in liquid helium. This opens a huge field for experimental investigations of Bose-Einstein condensation and of its influence on properties of solids.
- Published on 17 May 2010
Our understanding of elasticity, plasticity and failure in non-crystalline solids has greatly enhanced through atomic scale simulation. A new Colloquium paper In EPJ B reviews a variety of computational approaches that have been successful in elucidating the atomic scale phenomena that control the mechanics of amorphous solids. The constitutive theories that have been developed for describing mechanical response are briefly illustrated, as well as the prospects for testing the assumptions of these theories using simulation. The authors, M.L. Falk and C.E. Maloney, pose the most pressing open questions for substantiating these theoretical approaches, and ultimately for understanding and predicting the mechanical behaviour of amorphous solids.
To read the full paper "Simulating the mechanical response of amorphous solids using atomistic methods" by M.L. Falk and C.E. Maloney, European Physical Journal B click here.
- Published on 03 May 2010
Keiichiro Nasu reviews models of photo-induced structural phase transitions in relation to recent experimental results on unconventionally photoactive solids, where the relaxation of optical states results in macroscopic excited domains with new structural and electronic orders. Two key concepts, the hidden multi-stability of the ground state and proliferations of optically excited states are discussed. Taking the ionic to neutral phase transition in an organic charge-transfer crystal as example, the author documents the fundamental nature of photo-induced structural phase transitions. Further, Nasu recounts the details of the discovery of a new photo-induced phase of carbon, named "diaphite", located in between graphite and diamond. The mechanism of this photo-induced structural phase transition is discussed in terms of the proliferation of photo-generated inter-layer charge-transfer excitations in the visible regime.
To read the full paper 'sp3 domain in graphite by visible light and photoinduced phase transitions' by K. Nasu, European Physical Journal B click here.
- Published on 17 November 2009
An analytical theory explains why a probe molecule such as Na2 on the surface of a liquid 4He droplet creates soft vibrations which can be used to study the dynamics of the droplet surface with optical spectroscopy.
To read the full paper by Hizhnyakov, Tehver and Benedek click here
Microscopic modeling of electronic quantum nanodevices reviewed in a Colloquium paper by D. Taj, R.C. Iotti and F. Rossi
- Published on 02 November 2009
Quantum devices represent an important topic of modern nanoscience, characterized by its multi-disciplinary flavor where condensed matter physics, quantum theory, and information technology merge into a unique body of knowledge. In this Colloquium paper Taj and co-workes review and discuss how to work out a microscopic modeling of state-of-the-art electronic quantum devices. The emphasis is on the description of energy-relaxation and decoherence phenomena. Finally, the authors propose an alternative formulation of the problem in terms of a generalized Fermi's Golden Rule.
Click here to view the full text: [D. Taj et al., Eur. Phys. J. B 72 (2009)]
The unusual electronic and transport properties of graphene-based nanostructures reviewed in a Colloqium paper by Dubois, Zanolli, Declerck, and Charlier in EPJ B
- Published on 16 October 2009
Graphene-based nanostructures are expected to display the extraordinary electronic, thermal and mechanical properties and are thus promising candidates for a wide range applications and opening alternatives to present silicon-based electronics devices. This paper reviews the electronic and quantum transport properties of these carbon nanomaterials in which confinement effects are playing a crucial role. After reviewing the transport properties of defect-free systems, doping and topological defects are also proposed as strategy to tailor quantum conductance in these materials.
For further information see [S.M.-M. Dubois et al., Eur. Phys. J. B 72/1 (2009)]