Article dans Physical Review Materials "Plasmons in anisotropic Dirac System" - IM2NP - Equipe MQT (Roland Hayn)
Plasmons in anisotropic Dirac systems
Graphene is the most popular example of a two-dimensional Dirac system being characterized by a linear electron dispersion and extremely high electron velocity. But it is only one example of a large and new material class including also topological insulators and many other two-dimensional systems which were recently synthesized. That material class of Dirac systems is attracting at present an enormous research activity all over the world due to their exceptional material properties and the enormous potential for future applications. One is in the field of Dirac plasmonics using the coupling of collective charge excitations in two dimensions (surface plasmons) with light. Plasmonics applications are extremely wide spread reaching from nano medicine over optoelectronics and molecular sensing up to plasmic lasers. In difference to the already well established field of nanoplasmonics with noble metals, Dirac systems add a very interesting tunability in the tera-hertz or mid-infrared region which is not possible in noble metal plasmonics.
Researcher from the IM2NP in collaboration with colleagues from Germany and Spain [1] added now a new tunability to these Dirac plasmons by proposing to use anisotropic Dirac systems which were recently discovered [2] at the surface of topological insulators. Namely, the high spatial anisotropy between the electron velocities in opposite directions leads to a highly anisotropic plasmon dispersion (see Figure) which could allow applications like plasmon wave guides.
[1] R. Hayn, T. Wei, V.M. Silkin, J. van den Brink, Phys. Rev. Mat. 5, 024201 (2021)
[2] F. Virot, R. Hayn, M. Richter, J. van den Brink, Phys. Rev. Lett. 106, 236806 (2011)
Contact : Roland HAYN, équipe MQT - IM2NP
