Majorana fermions in superconductors are the subgap quasiparticle excitations that are their own antiparticles.

The thesis mainly contributes to the characterization of Majorana fermions as they appear in the Condensed Matter context.

Promotor: C.W.J. Beenakker, Co-Promotor: A.R. Akhmerov

Promotor: C.W.J. Beenakker, Co-promotor: M.T. Wimmer

Promotores: P. Stevenhagen, L. van Geemen Co-promotor: R.M. van Luijk

Promotor: G. J. Kroes

Heterogeneous catalysis is essential to many industrial applications. These catalysts are often comprised of supported nanoparticles, which contain various different surface sites.

Promotor: M.T.M. Koper, Co-Promotor: L.B.F. Juurlink

Promotores: P. Stevenhagen, L. van Geemen (Università degli studi di Milano), Co-Supervisor: Ronald M. van Luijk

The local ordering of atoms at the surface of a metallic particle determines its catalytic activity and selectivity. As energy systems of the future will be based on efficient catalytic conversion of small molecules in closed cycles, we study how structural effects of catalysts can be used to our ad…

The research aim of the Catalysis and Surface Chemistry group headed by Prof. Marc Koper is to probe and understand chemical reactions on well-defined, mostly single crystalline, surfaces at the molecular level.

Curved single crystals provide variable, but well-defined surface structures.

In this thesis integral points on affine del Pezzo surfaces are studied.

Surface plasmons (SPs) are surface waves at the interface between a dielectric and a good metal, and are formed by the interaction between light and the free electrons at the metal-dielectric interface. They provide strong field confinement for optical fields, opening new possibilities for enhanced…

Promotor: Peter Stevenhagen

Several techniques are explored for going beyond the born-oppenheimer static surface model for molecule-surface reactions.

Theorists have recently made substantial progress in simulating reactive molecule-metal surface scattering but still face major challenges. The grand challenge is to develop an approach that enables accurate predictive calculations of reactions involving electronically excited states with potential…

Promotor: P. Stevenhagen, Co-promotor: R.M. van Luijk

van Luijk

Improving environmental risk assessment of pesticides in surface waters

Majorana particles have been getting bad publicity: a claimed discovery in ultracold nanowires had to be retracted. Now Leiden physicists open up a new door to detecting Majoranas in a different experimental system, the Fu-Kane heterostructure, they announce in Physical Review Letters.

This thesis contains results on the arithmetic and geometry of del Pezzo surfaces of degree 1.In Chapter 1 we give the necessary background, assuming the reader is familiar with algebraic geometry.

Promotor: Prof.dr. C.W.J. Beenakker

This PhD thesis concerns the topic of arithmetic geometry. We address three different questions and each of the questions in some way is about counting how big some set is or can be.

Professor Carlo Beenakker has been awarded a FOM Projectruimte subsidy to build a theoretical model of a majorana gun, a very promising instrument for quantum computers.

The research presented in this thesis makes use of small molecules (as H2 , D2 and O2 ) on well-defined single crystal surfaces (flat Pt(111), flat Cu(211) and curved Pt(111)) to elucidate the role of surface structure and degrees of freedom in the reactant in specific surface reactions.

Promotor: M.T.M. Koper, Co-Promotor: L.B.F. Juurlink

Majorana meets a mermaid

Is it possible to successfully design self-assembling nano-scale protein skeletons for use as a vaccine platform?

Promotor: Prof.dr. G.J. Kroes

Promotor: Prof.dr. J.W.M. Frenken

How can we make make accurate predictions for reactions of molecules on metal surfaces?

The dissociation of CH4 into CH3 + H on a metal surface is the rate determining step in processes which produce hydrogen, such as steam reforming and catalytic partial oxidation. Ultimately, we want to study the dissociation of methane on Ni(111) and Pt(111) quantum mechanically while taking into account…

Aim: To develop and enable application of a practical, flexible, user-friendly platform to provide the scientific community with a tool to generate land surface products and its associated uncertainties and exploit these for data-intensive science.

This perspective addresses four challenges facing theorists whose aim is to make quantitatively accurate predictions for reactions of molecules on metal surfaces, and suggests ways of meeting these challenges, focusing on dissociative chemisorption reactions of H2, N2, and CH4.

This meeting will be devoted to recent advances in the operando investigation of reactivity at surfaces from both experimental and theoretical points of view.

Advanced sensing techniques require graphene with high quality and well-controlled surface chemistry.

Promotor: M.T.M. Koper, Co-promotors: A.I. Yanson, L.B.F. Juurlink

Promotor: Prof.dr. H.V.J. Linnartz, Co-Promotores: H.M. Cuppen, S. Ioppolo

PhD Defence

Promotor: E. Bouwman, Co-promotor: S. Bonnet

It is possible to treat the dynamics of the dissociation of hydrogen on metal surfaces quantum mechanically, while taking into account the motion in all six molecular degrees of freedom without making approximations. Because the approximations of neglecting surface phonons and electron-hole pair excitation…

Methods for accurately computing the interaction of molecules with metal surfaces are critical to understanding and thereby improving heterogeneous catalysis.

Promotor: M.T.M. Koper, Co-promotor: J.B.F. Juurlink

Theoretical physicist Carlo Beenakker has been awarded a €2m Advanced Grant by the European Research Council (ERC). He will use this to try to create the ideal building blocks for a quantum computer: ‘braided’ Majorana fermions. An ambitious project that may just lead to a major breakthrough.

Like a mixture of oil and water, lipid membranes separate into two liquid phases.

The surface and the edges of graphene are expected to provide higher sensitivity and specificity in detecting and characterizing single molecules. However fundamental physical limits exist in reaching an ultimate precision in detecting the dynamics of chemical and biological systems. The research in…

Catalysis is of extreme relevance in the production of everyday materials and plays a central role in many aspects of our life.

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