Editorial

This issue of Molecular Physics features the next in a new series of invited review articles that aim to highlight recent developments at the interface between physics and chemistry. The article ‘Single-Molecule Surface and Tip-enhanced Raman Spectroscopy’ by Dr. Bruno Pettinger at the Fritz Haber Institute of the Max Planck Society 1 provides a concise and critical account of Raman spectroscopy at its sensitivity limit of one molecule.

The past two decades have witnessed a rapid development of optical studies on single molecules and with spatial resolution beyond the diffraction limit. While a great deal has been learned, many exciting questions remain open. For example, the origins of phenomena such as photoblinking, spectral jumps and spectral diffusion, which can now be viewed directly at the single molecule level, are still poorly understood. The long tradition of Molecular Physics in connecting experimental findings with theoretical explanations provides an ideal forum to discuss these issues. In 2009, we started an initiative to explore recent nano-optical findings by publishing a special issue on Spectral Dynamics with Prof. Michel Orrit as guest editor 2.

Another intriguing topic in nanoscopic molecular physics concerns field-enhanced spectroscopy at the surface of metallic nanostructures. A recent article by Kühn et al. in Molecular Physics 3 presented results on the effect of a single gold nanoparticle on the fluorescence of a single molecule. Furthermore, the article by Schleifenbaum et al. 4 discussed diffusion in surface-enhanced Raman spectra. In his review Bruno Pettinger presents the historical developments that have led to pushing surface-enhanced Raman spectroscopy (SERS) to single-molecule sensitivity. In particular, he critically considers the works of the past decade and a half and questions the consistency of the data and interpretations provided in the literature. Dr. Pettinger has successfully combined scanning probe microscopy at ultrahigh vacuum and in air to perform ‘tip-enhanced’ Raman spectroscopy (TERS) under controlled conditions. This article provides an excellent overview both for scientists working in the field and others who would like to have a crisp account of where SERS and related methods stand today.

The Editors will welcome new research article submissions in these areas and will publicise such articles and other recently published related papers in conjunction with the review articles. Through the collection and presentation of stand-alone papers, which may be either directly or obliquely linked to each other, we aim to further develop the understanding of these areas in general.