Onderzoeksgroepen in het Quantum Matter & Optics onderzoeksprogramma onderzoeken elektronische eigenschappen van interacties van materie en lichtmaterie, met de nadruk op quantuminformatie.

Optical cavities are useful tools to enhance the interaction between light and matter, which is important to make good quantum emitters. However, it turns out that the cavities themselves (without any quantum emitters) are already interesting objects to study.

Promotor: Prof.dr. M.A.G.J. Orrit

Promotor: Prof.dr. D. Bouwmeester

Scattering of light in the presence of nano-structured materials, i.e. with features in the order of the wavelength of the light or smaller, reveals details of how light interacts with matter at the nanoscale.

Promotor: R. Gill, Co-promotor: P. Massart

Promotores: Prof.dr. C.U. Keller, Prof.dr. H.C. Gerritsen

Promotor: C. W. J. Beenakker, Co-promotor: J. K. Asboth

Why do black holes emit thermal radiation? And how does a closed quantum system thermalize?

A single self-assembled semiconductor quantum dot in a high-finesse optical microcavity - the subject of this thesis - is an interesting quantum-mechanical system for future quantum applications. For instance, this system allows trapping of an extra electron and thus can serve as a spin quantum memory,…

Wat weet het grote publiek over quantum en wat vindt men ervan? Ook daar denken onderzoekers binnen Quantum Leiden over na.

Quantum hardware comes with a different computing paradigm and new ways to tackle applications. Much effort has to be put into understanding how to leverage this technology to give real-world advantages in areas of interest for industries such as combinatorial optimization or machine learning.

This thesis investigates the contribution of quantum computers to machine learning, a field called Quantum Machine Learning. Quantum Machine Learning promises innovative perspectives and methods for solving complex problems in machine learning, leveraging the unique capabilities of quantum computers…

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

This thesis addresses questions on effectively using variational quantum circuits for machine learning tasks.

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

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

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

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.

The focus throughout this thesis will be on gathering fundamental studies of the detailed structure and composition of the electrode/electrolyte interface effect on the rate and mechanism of key electrocatalytic reactions.

Lezing

Quantum critical metals at vanishing fermion flavor number.

This thesis considers multi-prover commitment schemes whose security is based on restrictions on the communication between the provers.

We find ourselves in an era of transition, not just towards a more computing- and data-driven society but also away from unsustainable fossil fuels as an energy source.

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

Most of current public-key cryptography is considered insecure against attacks from sufficiently powerful quantum computers. Post-quantum cryptography studies methods to secure information resistant against such attacks. One proposal is isogeny-based cryptography, which bases its security on computational…

Spectroscopic studies on fluorescent single molecules in organic condensed matter does not only provide information about the molecule itself, but also its near environment. By suppression of phonon-induced broadening of spectral lines through cooling to low temperatures, small changes in the spectral…

What are the flows of C&DW (e.g. bricks, concrete, gypsum and wood) in the case study countries ? How to define the specification for each material to be quantified? What indicators should be used to identify the pattern of each C&DW management system? How to interpret the MFA results in relation…

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

Promotor: J.W.M. Frenken Co-Promotores: I.M.N. Groot; L.B.F. Juurlink

Promotores: Prof.dr. D. Bouwmeester, Prof.dr. A. Fiore (TU Eindhoven)

The aim is to develop methods to assess environmental and occupational exposure to (individual) pesticides, to be applied in epidemiological studies investigating pesticide exposure and human health. Furthermore, we aim to investigate the potential association between exposure to pesticides and Parkinson’s…

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.

This thesis is a collection of experimental attempts to enhance photoluminescence of fluorescent molecules and quantum dots with single gold nanorods (GNRs) and relevant applications.

Wat is onze toekomst met quantum en hoe betrekken we mensen daarbij? Om die vraag draaide het Gala voor Quantum en Samenleving in een uitverkocht TivoliVredenburg op 14 maart. Leidse onderzoekers Julia Cramer en Evert van Nieuwenburg waren erbij.

Zijn quantumcomputers de wetenschappelijke doorbraak van onze tijd? In deze podcast geeft natuurkundeprofessor Carlo Beenakker uitleg over quantumtechnologie.

Boter-kaas-en-eieren, maar dan met quantumeffecten. Zo leer je de beginselen van quantumtechnologie in een fluitje van een cent. Daar zet onderzoeker Evert van Nieuwenburg op in met zijn nieuwe start-up: QuantumPlayed. ‘Quantum is overal om ons heen en zo kan iedereen erover leren.’

De huidige en toekomstige quantumcomputers vormen dezelfde uitdaging als de laser in zijn begindagen. In theorie werd voorspeld dat de laser een bron van zeer speciaal, zeer krachtig licht zou zijn. Maar in die tijd waren er geen duidelijke toepassingen voor. Critici van het idee noemden het een probleem…

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

De nationale quantumcursus maakt de wereld van de allerkleinste deeltjes toegankelijker voor iedereen. Quantumexpert Julia Cramer is het gezicht van de cursus en was bij de lancering. En wat is daarvoor een betere plek dan Madurodam - waar alles klein is?

De P.C. Hooftprijs gaat komend jaar naar de dichter Alfred Schaffer. Schaffer studeerde van 1992-1997 Nederlandse taal- en letterkunde en was in 2017 gastschrijver aan de Universiteit Leiden. Schaffer won reeds vele prijzen. Naast zijn werk als dichter doceert hij Nederlands aan de universiteit van…

In this thesis, classes of strongly interacting quantum field theories, have been studied.

De Leidse natuurkundigen Carlo Beenakker en Bas Hensen ontvangen 35 miljoen euro in een consortium met onderzoekers van QuTech en de TU Delft. Ze gaan de fundamentele grenzen van de quantumfysica onderzoeken.

Promotor: C.A.M.J.J. van den Hondel, Co-promotor: Sandra de Weert

Quantumtechnologieën zijn wereldwijd in trek, maar Leidse studenten konden zich er tot op heden niet in specialiseren. Daar gaat de nieuwe master QIST (Quantum Information Science and Technology) verandering in brengen. Onderzoeker en docent Jordi Tura i Brugués: ‘We moeten de volgende generatie quantum-ingenieurs…