In the first part of this thesis we study the geometry of folding patterns.

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

“Transitional justice” is a field of practice, policy and study that focuses on the ways that societies respond to legacies of large-scale atrocities though tribunals, truth commissions, reparations, and other mechanisms.

LCD screens use liquid crystals which have a high degree of order, even though they form a fluid. A new theory maps out the interplay between order, temperature and symmetry. Publication in Physical Review X.

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.

For the first time ever, Leiden biologists have found that the ‘nose’ of spirochetes – worm-shaped bacteria – have a two-fold symmetry. A remarkable discovery, as the ‘nose’ of every other bacterium has been found to have a six-fold symmetry. First author Alise Muok wrote a popular blog about the findings…

Promotor: J. Zaanen

Promotor: Prof.dr.ir. J.W.M. Hilgenkamp, Prof.dr. J. van den Brink

Balsaminaceae is a diverse plant family characterized by a huge floral morphological diversity.

Promotie

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: H.J.M. de Groot

Lezing, Com(parative) Syn(tax) Series

Promotie

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

Mechanical metamaterials are man-made materials which derive their unusual properties from their structure rather than their composition.

Promotor: Prof.dr.ir. T.H. Oosterkamp, N. de Jonge

Peak Performance: Collaborative Crisis Management Before and During International Summits. This comparative case study probes into conditions for collaborative governance in the security organisation of international summits.

Promotor: C. W. J. Beenakker, Yu. V. Nazarov, Co-promotor: J. Tworzydlo

Promotor: Prof.dr. J. Zaanen, A. Parnachev

This dissertation is an experimental study of laser-generated, atmospheric pressure, transient toroidal helium plasmas.

Promotie

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.

Prof. Robbert Dijkgraaf used experiments and models from Leiden University for his tv lecture on symmetry. The lecture was broadcast live on channel 1. He showed that our DNA only twists in one direction using a plastic DNA model and he used a Chladni plate to show the symmetry of sound.

Knowledge and culture subproject 4:

Het project heeft plaats gevonden in de QMO groep onder begeleiding van Dr. Michiel de Dood en Dr.ir. Sense Jan van der Molen. De titel van de presentatie is:

Greenhouse gasses in the atmosphere and fertilizers in the groundwater have negative consequences for our environment. With an electrochemical process they can be transformed to more valuable and useful substances like fuel and alcohol. Chemistry PhD candidate Elena Perez Gallent discovered how this…

If three or more objects move around each other, history cannot be reversed. That is the conclusion of an international team of researchers based on computer simulations of three black holes orbiting each other. The researchers, led by the Dutch astronomer Tjarda Boekholt, publish their findings in…

The documentary Einstein’s Light by director Nickolas Barris shows in a dazzling manner what scientific breakthroughs resulted from the special friendship between Albert Einstein and the Leiden physicist Hendrik Antoon Lorentz. The documentary premiered at the Leiden International Film Festival on 2…

An international group of scientists, led by Leiden physicist Sense Jan van der Molen, has developed the first switchable molecular diode. You can turn this on and off through humidity. Vice versa, it is a humidity sensor at the nanoscale. Publication on 4 December in Nature Nanotechnology.

Knowledge and culture subproject 3:

Astronomer Donggang Wang, physicist Anne Meeussen and chemists Nick Gerrits and Elliot Mock: all four are receiving a Rubicon grant from the Dutch Research Council (NWO). This grant for young talent will enable them to spend two years doing research at a foreign university.

Publication in Proceedings of the National Academy of Sciences.

Former PhD, Bachelor and Master students of the Van Exter Lab

The specialisations Art History and Museum Studies both engage in critical perspectives and in current practices and the development of a professional network. The specialisation Art History puts emphasis on the analysis of art works within a museal and curatorial context. Our courses, taught by art…

The specialisations Art History and Museum Studies both engage in critical perspectives and in current practices and the development of a professional network. The specialisation Museum Studies focuses on the art museum and places it in an artistic, cultural, social and political context. Our courses,…

Quasicrystals are crystals with ‘impossible’ five-fold symmetries, which nevertheless were synthesized in the lab in 1982. Paul J. Steinhardt helped figure out their structure, but he didn’t stop at that.

Dutch speedskaters have been winning the most medals in speed skating at the Winter Olympics for years. How? Based on their intuition. Scientist Jeroen van der Eb of the Data Mining & Sports group of the Leiden Institute of Advanced Computer Science (LIACS) wants speedskaters to adjust their irons based…

Eight young researchers from Leiden University have received a Rubicon grant from the Dutch Research Council (NWO). This will allow them to conduct research at a top institute or university abroad.

The channel through which two cell components exchange material appears to form at the edge of their contact surface, and not in the middle. This was discovered by the Leiden physical chemists Jelger Risselada and Edgar Blokhuis together with researchers from the University of Lausanne in Switzerland.…

Lezing

Theoretical physicists research a special class of particles; Weyl fermions. They have found them to exhibit paradoxical behavior, in contradiction to a thirty-year old fundamental theory in electromagnetism. A possible application is a new kind of electronics—spintronics. Publication in Physical Review…

Lezing

The Dick Stufkens Prize 2020 for the best PhD thesis of the Holland Research School of Molecular Chemistry has been awarded to Dr Mark Koenis. Koenis graduated 21 February with the distinction cum laude on his thesis 'Advanced Spectra Analysis to Determine Complex Structure and Chirality'. He describes…

An overview of awards and prizes granted to our staff and students in 2021, as well as special appointments at Leiden University and other institutions.

Sumerian is a dead language that is not related to any other language. Howeverr, Bram Jagersma managed to compile a grammar of the language, based on inscriptions and clay tablets. Traces of the Sumerian number system can still be seen in our sixty-minute hour. Jagersma received his PhD on 4 Novembe…

Lezing