Molecular Physics seminar

Photonics of low-dimensional structures

by Alexey Nikitin, Bilbao

Europe/Stockholm
Room FB52

Room FB52

Description
Photonics plays an important role in different scientific areas and has become an interdisciplinary science. It studies generation, emission, transmission, modulation, signal processing, switching, amplification, and detection/sensing of light. Many of these exciting applications are relevant in our day-to-day life: from laser surgery, telecommunications and optical computing to military navigation systems and harvesting of energy.

A special place in photonics is allotted to infra-red (IR) light, which is the finger-print region of many organic molecules and a hardly reachable terahertz (THz) radiation used, for instance, in tomography and wireless communications. The growing interest in miniaturization of the IR- and THz-based devices induces the quest for novel materials/metamaterials capable to accumulate and transfer electromagnetic energy in small spaces.

A recent breakthrough in the science of two-dimensional (2D) materials (e.g. Nobel prize for the discovery of graphene in 2010) has generated a large interest in graphene photonics. In particular, it has been experimentally demonstrated that graphene can support surface electromagnetic waves (plasmons) in THz and IR ranges, which can be efficiently tuned by an external voltage [Nature 487, 77 (2012), Nature 487, 82 (2012)]. The plasmons can reduce the wavelength of light down to two orders of magnitude and thus dramatically compress the electromagnetic energy. This discovery has shown a huge potential of graphene for controlling the IR and THz light in nanoscale and, moreover, for merging 2D electronics and photonics. Here, we will consider 2D ("flatland") materials as a promising rich platform for manipulation of IR and THz waves. We will show how to launch and focus light in graphene sheets and s stripes, carbon nanotubes, thin polar layers and other low-dimensional structures [Nano Lett. 14, 2896 (2014); ACS Photonics DOI: 10.1021/ph500377u (2015)]. We will discuss both theoretical and experimental studies on 2D optics (optics in atomically-thick layers) [Science 344, 1369 (2014)] as well as the applications of 2D plasmonics to modern IR and THz microscopy of super-high resolution [Nano Lett. 13, 6210 (2013)].