Topological insulators are materials with special universal properties, which are protected against perturbations. Such properties are theoretically described by topology, a branch of mathematics concerned with the properties of geometrical objects that are unchanged by continuous deformations. Concretely, topological insulators are electronic materials that have a bulk band gap like an ordinary insulator but have […]
Periodic responses to nonperiodic energy inputs, such as oscillations, are hallmarks of living systems. Researchers have devoted considerable efforts to understanding and mimicking natural self-assembled structures and functions to systems composed of nonbiological components. This has rendered remarkable developments in regulating interparticle interactions to form static and dynamic self-assemblies. Dynamic assemblies can, under suitable stimuli […]
The development of luminescent organic radicals has resulted in materials with excellent optical properties for near-infrared (NIR) emission, like organic light-emitting diodes (OLEDs). Light generation in this range could be used for healthcare diagnosis and treatment to surveillance, communications and other security applications. Although an external quantum efficiency greater than 20% in electroluminescence has been […]
CFM • DIPC • DIPC Photonics
Modern technologies enable the design and nanofabrication of photonic devices for manipulation of optical fields on spatial scales much smaller than the wavelength of light. In particular, the resonant coupling of photons with collective electronic excitations in metals and two-dimensional materials, i.e., plasmons, can be used to engineer strongly enhanced near fields confined to the […]
CFM • DIPC • DIPC Photonics
As the top atomic monolayer lifts a few Å off the underlying bulk Au (111), ab initio electronic structure calculations show that for gaps >1.5 Å, visible light squeezes inside the empty slot underneath, giving optical field distributions 2 Å thick, less than the atomic diameter. Considerable attention has been paid in the past decades […]
CFM • DIPC • DIPC Photonics
Molecular vibrations couple to visible light only weakly, have small mutual interactions, and hence are often ignored for non-linear optics. Still, molecular vibrations dominate electronic, thermal, and spin transport in a wide range of devices from photovoltaics to molecular electronics as well as being of fundamental interest. Surface-Enhanced Raman Spectroscopy (SERS) is well-established for studying […]
Spurred by outstanding optical properties, chemical stability, and facile bioconjugation, plasmonic metals have become the first-choice materials for optical signal transducers in biosensing. While the design rules for surface-based plasmonic sensors are well-established and commercialized, there is limited knowledge of the design of sensors based on nanoparticle aggregation. The working principle of biosensors built around […]
An exciton can be described as an electron-hole pair in a crystal that is bound in a manner analogous to the electron and proton in a hydrogen atom. The exciton behaves like an atomic excitation that passes from one atom to another. In most cases, excitons are induced by an electromagnetic wave, a photon. Interestingly […]
Some materials have special universal properties protected against perturbations. Such properties are theoretically described by topology, a branch of mathematics concerned with the properties of geometrical objects that are unchanged by continuous deformations. So-called topological insulators are electronic materials that have a bulk band gap like an ordinary insulator but have conducting states on their […]
When the surface of a perfect conductor is structured at a length scale much smaller than the operating wavelength, geometrically induced surface electromagnetic modes can be supported. Owing to their similarities with the surface plasmon polaritons in the optical regime, these surface electromagnetic modes were named spoof surface plasmons. A new review provides a detailed […]