Thin films are omnipresent in our everyday life and are at the heart of modern technologies. With the advent of atomically thin films, such as graphene, the interest in the physics and chemistry of thin films has increased tremendously. The science and technology hinges on film growth, a complex and nonlinear phenomena that is still not fully understood from the experimental as well as theoretical points of view. In this Colloquium article, the newest findings in this fascinating field of research are described.

Polaritons, quasiparticles that result from the interaction of a photon with an electric or magnetic dipole, are omnipresent in several areas of physics. In this Colloquium, the theoretical and experimental studies of these interesting quasiparticles in diffusing vapor are discussed.

Silicon is universally recognized as the central ingredient of today’s computer and electronic technologies. Silicon not only benefits from a microelectronics fabrication technology developed over the last half century but also provides an ideal host environment for spins in the solid state, since there is negligible spin-orbit coupling and Si isotopes have zero nuclear spin. This review covers recent experimental advances and theoretical developments. Highlights include a description of methods to isolate and manipulate single electrons and their spins in gate-defined quantum dots and in individual dopant atoms, advances which point to the realization of quantum computation using spin quantum bits in a material with a long spin coherence time.

Where, when, and how do chemical processes enter our understanding of the Universe? This review surveys observations in various spectral windows of interstellar molecules and summarizes the chemical and physical processes during their formation and evolution. Emission and absorption bands in the visible, infrared, and submillimeter light spectra reveal a rich array of molecular (including organic) species up to complex polycyclic aromatic hydrocarbon and fullerene molecules and are the proof of complex chemistry occurring in the interstellar medium.

The 2012 Nobel Prize for Physics was shared by Serge Haroche and David J. Wineland. These papers are the text of the address given in conjunction with the award.

The 2012 Nobel Prize for Physics was shared by Serge Haroche and David J. Wineland. These papers are the text of the address given in conjunction with the award.

The principle of entropy maximization is the foundation of both equilibrium statistical mechanics and information theory. Recently entropy maximization has been recognized as a general principle with applications beyond these areas; in particular, entropy maximization allows one to deduce underlying probability distributions from incomplete information. In this article, we describe the maximum entropy principle and the ideas leading to its justification. We also describe the closely related maximum caliber principle, which is maximum entropy applied to dynamical trajectories and illustrate the power of these principles with several examples, such as image reconstruction, and nonequilibrium systems, such as molecular motors, neural spike trains, and a genetic toggle switch.

Active matter consists of self-driven particles (fish, birds, and many biological systems such as bacteria or cytoskeletal extracts) and exhibits intriguing nonequilibrium behavior such as flocking, swarming, bizarre fluctuations, and pattern formation. This article reviews continuum models for such systems, presenting the hydrodynamics of soft active matter.

The achievement of Bose-Einstein condensation with atomic gases has opened the way to novel superfluids, including those where the spin degrees of freedom play a determinant role in the time evolution of the fluid and/or in its equilibrium state. This article reviews recent theoretical and experimental advances in the domain of spinor Bose gases. It describes in particular the novel textures and topological defects that can emerge and discusses the connections between magnetic ordering and Bose-Einstein condensation.

The conversion of electricity into a photon flux with color quality resembling natural sunlight is desirable for artificial illumination. The ubiquitous incandescent light bulb, introduced in 1880 by Thomas Edison, satisfies this color quality requirement but suffers from a rather poor energy conversion efficiency of approximately 5%. This review focuses on device strategies to produce efficient organic white light-emitting diodes based on small molecular and polymeric semiconductors, which in the context of next generation lighting have a considerable technological promise.

Carbon nanotubes display a variety of electronic and thermal properties that depend on their length, diameter, and chirality and thus show considerable promise as fundamental building blocks for nanostructured materials. This review addresses the challenge of understanding and then exploiting the extremely high thermal conductivity of individual nanotubes, which can be the basic constituents of arrays and disordered mats. Experimental data are compared using consistent definitions of cross-sectional area, thereby providing for calibration and validation of diffusive and ballistic thermal transport calculations and molecular dynamics simulations.

In recent years it has become apparent that physical forces play a critical role in many biological processes. This is true for essential cellular processes such as migration, differentiation, and proliferation, all which depend on cellular adhesion to the environment. Experiments showed that the mechanical and adhesive properties of the substrate can guide their organization and behavior, with the central forces developed at the cell-material interface. In this review, the theoretical framework for understanding the physics of adherent cells is described. An introduction to soft matter and the biology of adherent cells is first provided. Then the role of elasticity and active force generation is analyzed from the dynamics of single adhesion sites through the shape of cells, to the large-scale organization of tissue.