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.

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

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

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,…

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…

Promotor: Ronald Cramer, Co-promotor: Serge Fehr

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

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,…

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

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.

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

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

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…

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?

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

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

The aim of this thesis is to present novel techniques for proving cryptographic schemes secure against quantum adversaries. Most results are within the context of an idealized model called the ‘quantum random-oracle model’.

We study the dynamics of individual emitters in micro cavities.

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

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.

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.

Quantum computing is a novel paradigm for computation, which is nearing real-world impact with the coming generation of limited, but nonetheless powerful quantum devices.

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 Divide & Quantum (D&Q) project offers various solutions to harness the power of quantum computers in the near term, proposing entire pipelines, from theoretical research, via implementation to real-world case studies in a number of disciplines, to science communication with the broader society.…

Welcome to the Hensen Lab! We are a young dynamic experimental research group starting at the Leiden Institute of Physics. Our lab addresses one of the key challenges of modern physics: understanding the interface between quantum mechanics and general relativity.

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

Cutting-edge technological innovation for businesses and consumers, enabled by top-tier research on space and the quantum world.

Quantum Information Science & Technology is a new joint degree master programme by Leiden University and TU Delft. Below you can find a video of the campus of the Science Faculty of Leiden University where a part of the lectures will take place. A video about the programme's content and structure…

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.

In my research, we developed a method to distinguish knots. A knot is a mathematical depiction of the everyday knot that occurs in ropes and cords.

How can we connect quantum technology and society for an open debate on its future implications and applications?

Thermodynamics is one of the founding scientific pillars that has helped us better understand heat engines, biology, ecosystems, and even black holes. While it fundamentally describes large systems by examining the bulk behavior of their constituents, it is anchored in the statistical equivalence of…

Quantum Delta NL, a research programme in which Leiden University participates, has been awarded 615 million euros from the National Growth Fund to help develop the Netherlands into a top player in quantum technology.

Quantum Information Science & Technology (QIST) encompasses the understanding, design, construction and investigation of quantum information processing systems, such as quantum computers, quantum communication networks, and quantum sensors.

In Quantum mechanics, particles can be in multiple positions simultaneously. Yet, when a measurement is made, the particle is found only in one place. Technology has come to a point where we may design experiments that will tell us how.

Promotor: C.W.J. Beenakker, Co-Promotor: A.R. Akhmerov

Quantum computers are a proposed fundamentally new type of computer. They aim to perform some computations much faster than previously possible by exploiting phenomena at the quantum scale, called superposition and entanglement.

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…

Cambridge University Press has published a new book co-authored by researchers from Leiden University, offering both an introduction to machine learning and deep neural networks, and an overview of their applications in quantum physics and chemistry — from reinforcement learning for controlling quantum…

The NEASQC project brings together academic experts and industrial end-users to investigate and develop a new breed of Quantum-enabled applications that can take advantage of NISQ (Noise Intermediate-Scale Quantum) systems in the near future. NEASQC is use-case driven, addressing practical problems…

Promotor: C.W.J. Beenakker, Co-promotor: M.T. Wimmer

The research group ‘Quantum and Society’ explores the boundary between quantum technology and science communication.

This thesis investigates how quantum, quantum-inspired, and hybrid quantum-classical computation can enhance key points of the automated machine learning (AutoML) pipeline under the constraints of noisy intermediate-scale quantum (NISQ) devices.

Born in Europe roughly 100 years ago, quantum physics brought forth a veritable technological revolution through semiconductors, lasers, fibre optics, and many other technologies that are today ubiquitous in our lives. Now, during the second quantum revolution, Europe can take the lead once more in…

The research group of Semonti Bhattacharyya at the Leiden Institute of Physics studies quantum transport measurements in Van der Waals heterostructures.

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…

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

This master’s programme combines Physics with Data Science. You will learn how physics has its own tricks to deal with big data and how techniques from machine learning and deep learning can be applied to classical and quantum data. The first focus of attention is on classical data, including data mining,…