Fields of Research

 Dynamics of Light and Matter

TAC brings together a broad range of fundamental and applied theoretical research activities on ultrafast spatio-temporal dynamics of ("soft" and "hard") nanomaterials with the physics of light and dynamics of advanced lasers and a large variety of advanced computational tools are developed and used on the dedicated high-performance computing platforms of the Nano-Modelling High-Performance Computing Lab (NM-HPCL) run by the TAC group.

Current foci of TAC's research interests are:

• metamaterials

  Optical metamaterials are the key to perfect lenses, 'invisibility' cloaks and slow and stored broadband light. We study the unique properties of metamaterials with a negative or negligibly small refractive index, research new ways how they can be realized and explore novel metamaterial phenomena at optical wavelengths and beyond. 

  

  • negative index metamaterials
  • ultralow and zero loss metamaterials
  • "trapped rainbow" storage of light in metamaterials
  • linear coupling of lightwaves in metamaterials
  • semiconductor metamaterials
  • molecular metamaterials

• nano-photonics and plasmonics

  Metal surfaces and interfaces can support surface plasmons - density waves of free electrons. These plasmon waves can interact with photons, opening the way to a novel realm of optics - plasmonics. When the metal surfaces are nanostructured, the possibility for true nanoscale photonics emerges at optical wavelengths. Using theoretical and advanced computational approaches that take on board microscopic spatio-temporal properties TAC studies the light-matter interaction in nanostructured metals and (molecular/nanoparticle) light scattering in structured polymer films and explores the ultrafast (sub-) femtosecond dynamics.

  

  • optics of metal nano-forests
  • functional plasmonics
  • active plasmonics
  • nano-photonic waveguides
  • organic plasmonics
  • Mie scattering by nanoparticles in polymers
  • nano-structural colour

• physics of photonic crystals

  Photons propagating in materials that are (periodically) structured on scales of about half or quater of the wavelength may experience them as "photonic crystals"  in a way similar to how electrons experience "normal" crystals. This may lead to novel effects such as the formation of so-called photonic band-gaps. We model the materials properties of ordered and disordered photonic "crystals" and explore the possiblity of photonic functionalities on the materials level.

  

  • physics of photonic crystals
  • polymer opals
  • photonic band-gap switching
  • Si-photonic crystal slab structures
  • control of spontaneous emission

• quantum nanomaterials and nanoelectronics

  Modelling the materials properties of and transport in nano-structured semiconductors, carbon nano-tubes and coupled spin systems on the basis of quantum theory.

  

  • semiconductor quantum dots
  • complex quantum dot nanomaterials
  • quantum modelling of molecules in and around carbon nanotubes
  • quantum dynamics and thermal transport in nanomaterials
     
     

• spatio-temporal bio-dynamics and soft-matter photonics

  TAC has pionered the theory for and modelling of the spatio-temporal dynamics of optical molecular motors. We study the way light interacts with (non-crystallised and disordered) molecular and biological materials in space and time and how light can be used to explore their dynamic structure and harnessed for control on the molecular level. 

  • spatio-temporal dynamics of optical molecular motors
  • quantum biodynamics
  • biophotonics

• structural dynamics of "soft" materials

  

  The physics of noncrystalised ("soft") materials as well as the realization of novel photonic "crystals" such as polymer opals involve complex spatio-temporal processes all the way from macroscopic scales down to the "flow" of single molecules (such as water) through carbon nanotubes.

  The TAC group developes new effective theoretical models (such as the "Maxwell model") describing the highly nonlinear flow and structural dynamics of anisotropic fluids (such as polymers) and simulates the microscopic (nonequilibrium) molecular dynamics of nano-confined water and formation of polymer opal films from (core-shell) polymer spheres on the basis of equilibrium and nonequilibrium molecular dynamics computer simulation.

  • rheo-chaos in Maxwell model fluids
  • 3D elastic turbulence in complex fluids
  • molecular transport through carbon nanotubes
  • formation of polymer opal films

• slow light science

  Slowing down light may dramatically increase the interation of photons with matter and lead to unprecedented nonlinearities, dramatically improved sensing or better efficiency of solar cells. TAC studies the physics of slow lightwaves in semiconductor quantum dot nanomaterials, metamaterial heterostructures, plasmonic nanomaterials, photonic crystals and fibres and graphene.

  

  • ultra-slow and stopped light in negative index metamaterial heterostructures

  • slow and fast light pulses in quantum dot optical amplifiers
  • slow light in photonic crystal waveguides
  • slow nonlinear optics
  • relativistic slow light effects

     

• physics of advanced lasers and spatio-temporal laser dynamics

  The TAC group has pioneered the field of spatio-temporal dynamics and quantum fluctuations of semiconductor lasers and continues to study the physics of advanced lasers, focussing on mirocavity or nano-lasers, new active materials and nonlinear dynamics and exploring novel concepts such as the "thermal laser".  We develop new theoretial approchaes for innovative gain materials (such as quantum dots), quantum fluctuations or novel laser concepts (such as the "thermal laser") and laser cavities (such as photonic crystal fibres) that may emit coherent radiation at new wavelengths and optical pulses with durations as short as femto- or attoseconds.

  • dynamics of semiconductor lasers
  • quantum fluctuations of semiconductor lasers
  • quantum dot lasers and amplifiers
  • semiconductor disc lasers
  • full-time-domain theory of ultrafast semiconductor lasers
  • femtosecond dynamics of microcavity lasers
  • spectral dynamics of fibre lasers and amplifiers
  • the "thermal laser" concept
  • random lasers

• femto- and attosecond dynamics

The conception and realisation of pulses of light that are as short as femto- or attoseconds has started to open up exciting new possibilities to observe and control the dynamics of electrons in atoms, nano-structures, biological media and the solid-state.

TAC studies the physics of ultrafast femto- and attosecond dynamics of semiconductors, plasmonic nanomaterials and bio-molecular media by a combination of theoretical and advanced computational simulation schemes involving and taking into account the propagation of coherent electromagnetic waves (with wavelengths from the THz to the soft X-ray regimes) and matter (on various levels of sophistication). 

• coherent femtosecond dynamics of semiconductors
• attosecond dynamics in nanoplasmonics
• ultrafast bio-molecular media

Strong and mult-faceted collaboration within the ATI as well as with academic partners and companies in the UK, Finland, Germany, Japan and the USA integrate our theoried and computer simulations with experimental and technological efforts and link them with innovative application.