Topical Issue: Ultrafast and ultrasmall

2013-02-25T00:00:00+01:00

Ultrafast physics and nanoscale research are two emerging scientific field that mate very well. This merger is currently developing into an independent, fruitful field of research.

Berlin (Germany) – Ultrafast physics and nanoscale physics are two highly successful fields of current research. Ultrafast science produces and analyzes events as small as attoseconds. It is often explored through analysis of atoms and molecules, where nanoscale research focuses on matter in the solid state form.
Both fields are merged in the latest Topical Issue of Annalen der Physik (www.ann-phys.org). The issue called “Ultrafast phenomena on the nanoscale” has been edited by renowned scientists in the correspondent fields: Peter Hommelhoff and Matthias Kling from Max-Planck-Institute of Quantum Optics, Garching, Germany, and Mark I. Stockman from Georgia State University, Department of Physics and Astronomy, Atlanta, USA.
Almost all important electronic processes in solids take place in sub-femtoseconds to picoseconds, whereas intriguing effects related to nanoscale phenomena (for example, the steering of electronic matter waves) take place over nanometer distances. Joining these two fields is only natural, because their intrinsic time and length scales match. In fact, ultrafast phenomena on the nanoscale is currently developing into its own, independent field of research. This fertile encounter can be explored in various directions. For example, ultrafast laser pulses can be utilized to probe electronic behavior in solids, and, vice versa, the electronic response of the optically driven electronic system might lead to new (nonlinear) effects. The large, and still growing, field of ultrafast plasmonics is the currently most visible offspring of this approach.
The collection of contributions in the special issue reflects the various directions from which the cross-section of “ultrafast and nanometer-small” science can be tackled. For example, F. Faisal, one of the fathers of multiphoton processes in strong laser fields, discusses related effects in the hottest nano-material currently explored: grapheme.
In a review article, by J.-Y. Bigot and M. Vomir report on ultrafast magnetization dynamics in nanostructures. Other articles treat the influence of inhomogeneous electric near-field distributions near nanoscale structures on high harmonic generation processes. Here, the decay length of the near field is so small that the trajectories of the electrons involved in the high-harmonic generation process are modified.
Further topics include the investigation of strong-field phenomena in electron emission from a tip array and the study on electron emission mechanisms of ultrashort-pulse-driven tips. Several papers turn the perspective around to study the ultrafast response of near-field, plasmonic, and surface effects. Another collection of articles is devoted to the ultrafast response of artificial atoms, mostly quantum dot structures. Novel techniques are the focus of two articles. One discusses imprinting XUV phase grating on wide-band seminconductors to probe the evolution of free carrier dynamics with the help of a time-delayed infrared pulse; the other shows how highly non-linear effects in a photonic structure can be used to switch light with light.
http://onlinelibrary.wiley.com/doi/10.1002/andp.v525.1-2/issuetoc

Topical Issue: A Snapshot of Plasmonic Sensors

2013-01-18T00:00:00+01:00

Biosensing is one of the most prominent application fields of modern plasmonics. Modern nanofabrication schemes and other methodological advances enable new fascinating possibilities in this emerging scientific area.

Berlin (Germany) – Plasmonics is a steadily developing field that offers really fascinating promises not only for fundamental science but also for a wide range of potential applications. One of the most prominent subjects is the area of biosensing making use of the high-field confinement offered by surface plasmon modes, a success story that started with the discovery of surface-enhanced Raman scattering. New sophisticated nanofabrication schemes open up fascinating possibilities of tailoring und structuring optical fields on the subwavelength scale to create optimized conditions for the interaction with molecular species.
The recent Topical Issue of Annalen der Physik (www.ann-phys.org) provides a snapshot of the variety of research in this fascinating area of modern plasmonics. Renowned European scientists function as the editors of the issue: Stefan Maier, co-director of the College’s Centre for Plasmonics and Metamaterials Imperial College London (UK), Mikael Käll, head of the Division of Bionanophotonics at the Department of Applied Physics at Chalmers University of Technology in Gothenburg (Sweden), and Liberato Manna, head of the Nanochemistry Department at the Istituto Italiano di Tecnologia in Genoa (Italy) [1].
A whole wealth of information throughout the field of plasmonics is offered by the special issue, starting with reports on nanofabrication techniques. A review article describes nanostructures for surface-enhanced Raman scattering [2]. Various nanoplasmonic devices can be fabricated using top-down methods such as electron beam lithography, electroplating and focused ion beam techniques. Theoretical simulations are presented on model nanostructures in order to understand the electrical field distribution.
A second review deals with the concepts and implementations of phase-sensitive surface plasmon resonance (SPR) biosensors, providing a tutorial on phase detection in SPR sensing [3]. Conventional SPR sensors have been extensively explored and applied, but it still lacks sensitivity for the detection of relatively small and low copy number compounds. Phase-sensitive SPR has recently emerged as an upgrade of this technology, which enables to solve the sensitivity problem. Annalen der Physik offer free access to both review articles.
The primary research articles included can be loosely divided into work reporting advances in sensing techniques and methodologies, from waveguide-based surface plasmon-polariton sensing, fiberoptic sensors, to comparisons between localized surface plasmon resonance with conventional Fabry-Pérot-type sensors, and into work primarily dealing with materials related aspects, focusing particularly on how surface quality and controlled surface modifications affect sensing performance. The issue closes with a Rapid Research Letter on laser-assisted substrate generation for surface enhanced Raman scattering.
[1] Ann. Phys. (Berlin) 2012, 524 (11), A155; DOI: 10.1002/andp.201200753
[2] A. Gopalakrishnan et al., Ann. Phys. (Berlin) 2012, 524 (11), 620; DOI: 10.1002/andp.201200145
[3] Y.H. Huang et al., Ann. Phys. (Berlin) 2012, 524 (11), 637; DOI: 10.1002/andp.201200203