Geometric phases lead to a nontrivial interference result when an electron's different quantum mechanical paths choices encircle a magnetic coil in an Aharonov-Bohm experiment.

This thesis aims to demonstrate how the achromatic nature and design flexibility of liquid-crystal optics can be used to improve high-contrast imaging instruments to facilitate detailed exoplanet characterization.

PhD defence

On May 17th, Arthur Crucq succesfully defended his doctoral thesis and graduated. The Leiden University Centre for Linguistics congratulates Arthur on this great result.

The main focus of this thesis is the behaviour of two-dimensional materials, namely (anti)-ferromagnetic materials in the first two chapters, which show topological phases, and energetic square ice in the third and fourth chapter.

Promotor: S.M. Verduyn Lunel, Co-promotor: O.W. van Gaans

This thesis is is made of three parts. The first part describes a generalization of the Chabauty's method, that can be used to determine the rational points of a curve such that s+g>r+1, where g is the genusof the curve, r is the rank of the Mordell-Weil group of the jacobian of the curve and s is…

A tidal basin is an inland sea which is almost entirely enclosed by land and connected to the open sea by a tidal inlet. Through the tidal inlets interaction takes place between the tidal basin and the open sea.

Knowledge and culture subproject 3:

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.

Promotor: J. Zaanen

Galaxies are environments where gas coalesces, cools, and is converted into stars. However, it remains unclear the exact mechanisms through which galaxies acquire, redistribute and lose their gas.

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

The lipid matrix in the stratum corneum (SC), the upper layer of the skin, plays a critical role in the skin barrier. The matrix consists of ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs).

This thesis describes the functional analysis of the Arabidopsis AHL15 gene.

The elementary excitations of magnets are called spin waves, and their corresponding quasi-particles are known as magnons. The rapidly growing field of Magnonics aims at using them as information carriers in a new generation of electronic devices, (almost) free of electric currents.

The lipid matrix of the skin's stratum corneum plays a key role in the barrier function, which protects the body from desiccation. The lipids that make up this matrix consist of ceramides, cholesterol, and free fatty acids, and can form two coexisting crystalline lamellar phases: the long periodicity…

Promotor: A. Doelman, Co-promotores: P.J.A. van Heijster; A. Zagaris

The map application includes information from old and new buildings archaeological projects. This makes it possible to investigate whether water facilities (wells, cisterns) and waste facilities (cesspits, sewers) were the privilege of Leiden’s wealthy elite in the late 16th and 17th centuries or whether…

Promotor: J. Zaanen, Co-Promotor: V. Juricic

One of the effects of climate change is the phenomenon of desertification, a process that occurs in semi-arid and arid areas and causes land degradation as well as vegetation loss. Due to the lack of resources, vegetation self-organizes to sustain itself by forming large-scale spatial patterns.

Vast, often populated, areas in dryland ecosystems face the dangers of desertification.

Knowledge and culture subproject 3:

Leiden University and the University of Amsterdam, together with Heritage Leiden and Region, are developing a map application of historical Leiden.

On 11 May 2017, The Ocean Cleanup revealed a new design for its cleanup system. LAPP was there!

Promotor: A. Doelman, Co-promotor: J.D.M. Rademacher

What are key regulators of plant ageing that can reverse ageing in plants (rejuvenation), and how can we use this knowledge to improve crop plants?

Leiden University is currently working on the new Gorlaeus Building, a sustainable modern building for the Faculty of Science. To make room for the phase 2A construction work, a plane tree of over 20 metres in height was moved on 17 December. The tree has been conserved. Its new home will be on the…

How should we deal with the post-corona phase? In a video (in Dutch) for the Association of Public Administration, Erwin Muller, Professor of Safety, Security and Law at Leiden University and former vice-chair of the Dutch Safety Board, reflects on the recovery phase and the corona crisis.

Promotor: Prof.dr. M.L. van Hecke

With the help of quantum mechanics, digital quantum hardware may be able to tackle some of the problems that are too difficult for ordinary computers. But despite these expectations and the ongoing effort of the research community, reliable quantum computers are not yet realized in a lab setting.

PhD defence

Promotor: Prof.dr. M.L. van Hecke, Co-Promotor: Prof. dr. V. Vitelli

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

Dorothea Schulz & Martin Hense

This thesis presents the first synthetic peptides ADP-ribosylated on serine, threonine, tyrosine, arginine and cysteine.

In the early universe, the dynamics of the Higgs field can give rise to many interesting phenomena.

Promotores: Bas Edixhoven, Jean-Benoit Bost, Co-promotor: Robin de Jong

Promotor: Arjen Doelman, Co-promotor: Vivi Rottschäfer

And the construction has started! Students of the Leiden Science study associations ceremoniously hammered down the first poles of the new Gorlaeus on Tuesday morning. By doing so, they initiated the second phase of the construction of the second part of the new building.

Lecture

This thesis covers various applications of topology in condensed matter physics and quantum information.

Promotor: G.A. van der Marel, Co-Promotor: J.D.C. Codée

In design optimization problems, engineers typically handcraft design representations based on personal expertise, which leaves a fingerprint of the user experience in the optimization data. Thus, learning this notion of experience as transferrable design features has potential to improve the performance…