"Graphene nanophotonics: Smaller, stronger, faster"

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Understanding and controlling the interaction between light and matter is fundamental to science and technology - from probing entanglement in quantum physics to optical networks for information technology. Using traditional optics, light can only be controlled on length scales down to the wavelength of light, the classical diffraction limit. This limit has huge consequences, setting stringent boundaries for a host of phenomena. In recent years plasmonics has emerged as a means to beat this apparent limit. The key attribute of plasmon resonances, typically observed in nanoparticles of gold and silver, is the ability to concentrate optical energy into volumes well below the diffraction limit. This light focussing property gives rise to many potential applications, from photo thermal treatment of cancer to light harvesting in enhanced solar cells.However, the field of plasmonics currently stands at a cross-road. The enormous potential of plasmonics as a means to manipulate light at the nanoscale is blocked by ohmic losses associated with the metals used; these losses ultimately set limits on light focussing and energy concentration. In this project I will explore a radical alternative by replacing conventional metals with new atomic scale, graphene-like layered materials. The ultimate goal is to overcome the critical limitations which currently hold plasmonics back, and thereby define future directions in the field. The three broad aims are:(1) Smaller - I will study the fundamental limits of energy concentration in plasmonics. Efforts will concentrate on developing and optimising platforms in promising new plasmonic materials based on the atomically layered structure of graphene.(2) Stronger - Energy concentration comes at a heavy price due to high absorption losses, which normally limits the plasmon lifetime to a few short femtoseconds. Recent results suggest absorption losses can be overcome by utilizing amplifying gain materials, which will enable active functionalities in these new plasmonic materials.(3) Faster - Atomic scale materials will bypass the problems associated with absorption, and will transform our ability to manipulate light on ultrafast timescales. This has enormous consequences, with potential applications for switching and nonlinearity, both vital for information processing with light. An ambitious plan is laid out, through which the vision of manipulating light on extreme sub-wavelength length scales will be made possible. This grand-scale project will unlock the true potential of ultrathin plasmonic materials for real-world photonic and optoelectronic devices.