Nanoscale Science Department
Research efforts in the Department are centered on nanoscale science and technology with a focus on the bottom-up paradigm. The aim of the interdisciplinary research at the interface between physics, chemistry and biology is to gain control of materials at the atomic and molecular level, enabling the design of systems and devices with properties determined by quantum behavior on one hand and approaching functionalities of living matter on the other hand.
When a single electron is made to tunnel across a vacuum gap, it may occasionally produce not just one, but two photons at a time. When these very rare events are produced in excess, the result is a phenomenon known as photon superbunching. With this finding, we have expanded the range of fundamental processes that can be controlled in a tunnel junction environment.
The strong spin-orbit coupling in three-dimensional topological insulators imparts a transversal spin Hall effect supported by their bulk states. It is demonstrated that the resulting spin accumulation at the lateral edges of Bi2Te2Se nanoplatelets can be effectively read out at room temperature through the local detection of a helical, bias-dependent photoconductance. The spin accumulation is further supported by the observation of a finite bias-dependent Kerr angle at the nanoplatelet edges.
Catalytic properties cannot be understood without a detailed knowledge about the atomic structure of the catalyst. Here, we provide insight into the morphology of an atomically well-defined cobalt oxide oxygen evolution and hydrogen evolution catalyst supported on a gold substrate. Under operando conditions, the catalyst undergoes structural changes from one oxide phase into another, but persists as a thin layer. This highlights the importance of the supporting gold substrate in stabilizing the catalytically active oxide phases in the electrochemical potential window and explains synergetic effects between gold and oxide film.