Surface polaritons in the mid infrared have emerged as a versatile platform for extreme light confinement and tailored nanophotonics [1,2]. These light-matter coupled modes can be hosted on two-dimensional materials such as graphene or hexagonal boron nitride. Whereas surface plasmons have been successfully modulated in gapless graphene, semiconducting layered materials and heterostructures...
In solid state physics, the electronic structure is often explained by examples of periodic systems. In reality, quasicrystals of metallic alloys with aperiodic atomic structure are well-known, whereas their valence electronic structure is still under debate [1]. Moreover, only very recently their unoccupied electronic structure has been studied [2]. In this contribution, we present...
Stacked layers of copper-phthalocyanine (CuPc) and PTCDA on Ag(111) represent a structurally well-defined model for an organic donor-acceptor interface above a metal substrate. We investigate the excitation dynamics of this system by means of two-photon photoemission (2PPE). Besides direct 2PPE from the CuPc HOMO and photoemission involving the n=1 and n=2 image potential states (IPS), we...
BiTeI is a layered semiconductor without inversion symmetry. Strong spin-orbit coupling leads to a giant Rashba-splitting of the BiTeI surface and bulk bands. In general, semiconductors exhibit longer excited carrier lifetimes than metals and are thus favorable for spintronic applications. Crystalline BiTeI is known to cleave along the van-der-Waals-bonded layers of Te and I. This results in...
