The research program of the QO group has three leading themes: Optical Physics, Quantum Optics, and Photon-Matter Interactions. We work mostly at the boundaries between these themes with entanglement as a bridging and binding agent.

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

The quantum nature of matter and light has grown into a broad and fruitful research field for theorists and experimentalists alike. It combines foundational research with toward applications, the most well known of which is the quantum computer.

The quantum nature of matter and light has grown into a broad and fruitful research field for theorists and experimentalists alike. It combines foundational research with toward applications, the most well known of which is the quantum computer.

Advancing the understanding of the interaction of light and matter on the single-quantum level is important for near-future quantum technologies but also to answer fundamental questions.

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

Research in the van Exter lab focuses on quantum aspects of light and light-matter interaction. One of our long-term goals is to develop a reliable quantum memory, based on a single emitter in an open micro cavity.

The master’s specialisation Research in Physics, Quantum Matter and Optics at Leiden University offers a thorough experience on the front line of physics research with a practical training of communicative and computer skills. The programme focuses on Condensed Matter problems, such as Molecular Electronics,…

The Clinical Epidemiology department at the LUMC has set up a series of lectures for asylum seekers. The series has become a huge success.

Promotor: Prof.dr. D. Bouwmeester, Co-promotor: M.P. van Exter

Pushing the boundaries of quantum theories – that’s exactly what the physicists at Leiden University excel at. Researchers in Leiden are launching eight new quantum research projects as part of the Quantum Limits consortium.

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,…

Quantum position verification (QPV) - the subject of this thesis - is a novel way to authenticate unknown nodes in a quantum network without the need to physically meet up.

This thesis covers several aspects of quantum algorithms for near-term quantum computers and its applications to quantum chemistry and material science.

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.

Quantum computing represents a fundamentally new computational paradigm, capable of addressing problems that are intractable for classical computers.

During my PhD research, I studied the photon statistics of light emitted by a microcavity that contains a single quantum dot (QD) on resonance.

Promotor: Prof.dr. D. Bouwmeester, Co-Promotor: M.J.A. de Dood

This dissertation focuses on investigating the public communication around quantum science and technology that may affect public engagement.

Promotor: D. Bouwmeester, Co-promotor: D. Kraft

Since the early 1990s, one can isolate the optical signal of a single molecule and single-molecule spectroscopy has quickly grown into an important research field.

We study the dynamics of individual emitters in micro cavities.

This thesis advances automata learning, a key area in computer science, with applications in software verification, biological analysis, and autonomous technologies. It explores three main themes: first, it introduces a passive learning algorithm for generating compact probabilistic models from positive…

Surface acoustic waves (SAWs) are mechanical waves that travel along the surface of a material and find many applications in modern technologies due to the ease of excitation on piezoelectric substrates via interdigital transducers (IDTs).

Top scientists of three Dutch universities are working on software and systems for quantum computers. Researchers of the Leiden Institute of Advanced Computer Science (LIACS) and the Leiden Institute of Physics (LION) are developing new algorithms to make those super computers work. The coming years,…

In this thesis, Quantum computing, norms, and polynomials, we investigate the interplay between quantum mechanics, complexity theory, and functional analysis, three central areas of physics, computer science, and mathematics, respectively.

Single-molecule spectroscopy has become a powerful method for using organic fluorescent molecules in numerous applications.

Quantum annealing belongs to a family of quantum optimization algorithms designed to solve combinatorial optimization problems using programmable quantum hardware. In this thesis, various methods are developed and tested to understand how to formulate combinatorial optimization problems for quantum…

Kiem project: How can metaphors be used to enhance societal engagement with quantum science and technology, and what factors influence their acceptance or resistance among experts and laypeople?

Promotor: Ronald Cramer, Co-promotor: Serge Fehr

This thesis is a collection of theoretical works aiming at adjusting quantum algorithms to the hardware of quantum computers.

To address the computational intractability of quantum system design, this research presents a framework that reduces quantum states and circuits to symbolic forms, enabling verifiable and interpretable analysis through classical satisfiability solving.

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

All the data stored and processed by our computers is encoded as sequences of zeros and ones, called bits. Quantum computers offer an alternative to this traditional way of encoding and manipulating information.

This thesis probes under what conditions quantum computing presents an advantage over classical computing.

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

Leiden physicists have created a light source that emits individual particles in an identical state through optical fibers. Using this setup, their measurements can last longer and are more efficient, meaning they can perform more in-depth research on bizarre quantum effects, such as interference and…

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

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

Quantum computing is an emerging technology, which holds the potential to simulate complex quantum systems beyond the reach of classical numerical methods.Despite recent formidable advancements in quantum hardware, constructing a quantum computer capable of performing useful calculations remains challenging.In…

How can the law provide legal safeguards for the save introduction of quantum technology for consumers, and how can these safeguards be examined and interpreted through interdisciplinary collaboration?

The field of exoplanet research is rapidly advancing through the development of new technology, observing techniques, and post-processing methods.

Scientists need individual photons for quantum cryptography and quantum computers. Leiden physicists have now experimentally demonstrated a new production method. Publication in Physical Review Letters on July 23rd.

Exploring the application of game-theoretic frameworks to quantum physics, this study creates novel AI training methods for the precise control of quantum systems.

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…

Exploring the integration of AI and quantum computing, this study adapts Knowledge Representation and Reasoning (KRR) to enhance quantum circuit simulation and optimization.

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.