The behaviour of strongly correlated electron systems, such as high-temperature superconductors, defies explanation in the language of ordinary quantum theory. A seemingly unrelated area of physics, string theory, might give physicists a better understanding of the weird behaviour of these kinds of…

In this thesis we use Josephson and noise scanning tunneling microscopy for the study of conventional, unconventional (iron-based) and disordered superconductors. On the one hand, Josephson scanning tunneling microscopy allows us to directly visualize the superfluid density with high spatial resolut…

Online services are stored on servers in data centres. Remko Fermin researched methods to make the memory in data centres more energy efficient.

German scientists and NASA have developed a bacteria-killing coating for space toilets. With this coating they hope to protect astronauts in space stations from pathogens. Professor of Biological chemistry Nathaniel Martin sheds light on the discovery: 'You don't expect nasty bacteria up there, but…

Since 2015 the United Nations have declared 11 February the International Day of Women and Girls in Science. Leiden University organized a public event for over a hundred visitors. In between a lecture on the building blocks of life and a talkshow on the impact of science on society, high school students…

Koen Bastiaans and his colleagues discovered a new quantum liquid unlike anything ever seen. They did it by using a technique that can be compared to listening to the sound of raindrops falling on a roof. Publication in Science 29 October.

Matthias Flór receives the KHMW Graduation Prize in Theoretical Physics for his master's thesis. His research on exotic superconductors at Leiden University and TU Delft struck a chord with the jury. The jury unanimously chose to award Flór noting that ‘he demonstrated impressive technical abilities…

Physicist Remko Fermin from Leiden University was awarded a Rubicon grant from NWO. He will use it to study superconducting diodes that could contribute to reducing the CO2 emission of data centres.

Experimental physicist Jan Aarts has received a FOM Projectruimte grant of 545,000 euro. He will use the budget to study the interaction between superconducting currents and ferromagnetism. In the future, this might lead to computer memory with negligible energy consumption.

In their quest for materials that conduct electricity without resistance at moderate temperatures, scientists usually work on their chemical make-up. Now Leiden physicists have come up with a radically new approach: pinching holes in a periodic pattern. Publication in SciPost.

Promotor: E.R. Eliel, Co-Promotor: M.J.A. de Dood

The university is committed to providing an accessible learning and working environment for students and staff. They should be able to feel at home at our faculty. That is why there is now an all-gender toilet in every humanities building to contribute to that feeling of recognition and safety.

Research groups in the Quantum Matter & Optics programme investigate electronic properties of matter and light-matter interactions with emphasis on quantum information.

Electrons that spin synchronously around their axis, turn out to stay superconducting across large distances within magnetic chromium dioxide. Electric current from these electrons can flip small magnets, and its superconducting version could form the basis for a hard drive without energy loss. Publication…

Physics professor Jan Aarts starts a collaboration with chip manufacturer Intel to perform fundamental research in low-power, cryogenic computing.

For the first time, physicists have visualized the ‘melting’ of electrons inside a special class of insulators. It allows electrons to move freely and turns the insulator into a metal and possibly later into a superconductor. Publication in Nature Physics.

STM scanning experiments on poorly conducting materials are challenging, and can cause a distortion effect. A new model corrects for this effect, allowing physicists to better study materials in their quest to understand unconventional superconductivity. Publication in Physical Review B as Editor’s…

Liquid nitrogen, frozen fruit and levitating market-goers. On Friday 8 April, visitors to the weekly market in the Merenwijk district were exposed to superconductivity. What is it exactly? And what does it look like? Young and old were impressed by the experiments demonstrated by Leiden students from…

The Leiden Institute of Physics has been awarded three out of twelve available grants from the FOM Projectruimte. Principal Investigators Milan Allan, Stefan Semrau and Carlo Beenakker all receive around 400,000 euro for their research.

A Josephson junction is a device where a thin insulating barrier or a nanostructure is placed between two superconducting leads. Such a junction is essential to superconducting qubits that store quantum information due to its anharmonic spectrum.

Our group explores the larger domain of quantum measurement. In particular we investigate two themes that are closely connected: The detection of specially prepared quantum states of light and understanding and characterizing quantum photon detectors.

We don’t understand how some materials become superconducting at relatively high temperatures. Leiden physicists have now found a surprising connection with auxiliary black holes. It enables us to use our knowledge of black holes on the mystery of high-temperature superconductivity. Publication in Nature…

Jan Zaanen, Professor in Theoretical Physics of condensed material, has been awarded a Spinoza prize. His pioneering ideas about the collective behaviour of quantum particles and high temperature superconductivity have often given him the reputation of being something of a rebel.

In this thesis we study quantum transport phenomena on the nanometer scale, in two classes of materials: topological insulators with induced superconductivity and graphene superlattices.

Cryogenic memories, antibiotic treatment for urinary tract infections and recycling plastic sustainably. These are the subjects of the three NWO-XS grants awarded to Leiden Science researchers.

String theory has come under fire in recent years. Promises have been made that have not been lived up to. Leiden theoretical physicists have now for the first time used string theory to describe a physical phenomenon. Their discovery has been reported this week in 'Science'.

A couple of years ago, theoretical physicist Carlo Beenakker tracked down the Majorana particles and inspired Leo Kouwenhoven from TU Delft to try to create them in a superconducting nano-structure. He succeeded in doing so in 2012, and the news made headlines around the world. But a lot of work still…

From the Big Bang to superconductivity. Many ground-breaking discoveries have been made in Leiden University’s long history.

As an alternative to the diving board shaped force sensor, we are now developing a magnetically levitated small superconducting particle – or ‘Lead Zeppelin'' – as our mechanical resonator. We explore routes towards detection of gravity between small objects.

Materials with strongly correlated electrons show some of the most mysterious and exotic phases of quantum matter, such as unconventional superconductivity, quantum criticality and strange metal phase.

Our cantilevers have a low intrinsic damping rate: this enables us to measure with low noise, since damping is proportionate to noise. However, when the magnet is close to the surface of a sample we want to study, we measure a much higher effective damping rate. This is caused by magnetic interaction…

In condensed matter systems electron-electron interactions, negligible in everyday metals, can dramatically alter the electronic behavior of the system. Examples of such altered behavior include high-temperature superconductivity and modulation of the electron density.

PhD defence

The Copenhagen interpretation of quantum mechanics states that a measurement collapses a wavefunction onto an eigenstate of the corresponding measurement operator.

Leiden University is committed to reducing our water consumption.

This thesis presents the results of a study on the interfaces of insulating oxides with and without the insertion of a magnetic layer.

Schalm

Physicists at the Leiden Institute of Physics (LION) conduct fundamental research into physical phenomena. They are inspired by curiosity and the desire to know more about the world in which we live. This research has always paved the way for new practical applications. These are something that the…

Physicists at the Leiden Institute of Physics (LION) conduct fundamental research into physical phenomena. They are inspired by curiosity and the desire to know more about the world in which we live. This research has always paved the way for new practical applications. These are something that the…

MRFM combines the principles of magnetic resonance and atomic force microscopy.

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

Leiden physicists have developed a way to address how accurately a superconducting single photon detector (SSPD) can be characterized by detector tomography. SSPDs are not fully understood, and tomography is a key element to determine how these devices detect light. A better understanding of these detectors…