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

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 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…

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

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

The main topic of this PhD thesis is the Arakelov ray class group of a number field, an algebraic object that contains both the ideal class group structure and the unit group structure.

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…

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.

Many important topics in computer science, such as the correctness of software, the efficiency of algorithms and the modeling of complicated systems, depend on sound theoretical underpinnings. In the Theory group, we study these fundamental building blocks and develop verification methods to prove system…

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

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.

Assistant Professor Vedran Dunjko and his team received a gift from Google to support their quantum research. The research focuses on whether quantum computers can provide new ways of understanding the mysteries of high-energy physics.

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.

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

Shell cooperates with theoretical physicists and chemists of Leiden University to research how quantum computer algorithms can help simulate complex molecules.

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.

The Algorithms and Software Technology (AST) research programme performs fundamental research in the areas of algorithm design and analysis.

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

Promotor: Ronald Cramer, Co-promotor: Serge Fehr

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

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,…

Researchers found a way to run programmes that should be impossible to carry out on an imperfect quantum computer. Such programmes are very computationally demanding and the quantum computers that currently exist are not yet up to that task. Unless you use a clever trick, Simon Marshall and Vedran Dunjko…

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

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

Proving a quantum computer to be quicker than a normal one is one step closer. After a breakthrough in speeding up classical algorithms, researchers Vedran Dunjko and Casper Gyurik showed that only one quantum algorithm could beat its classical counterpart. They discuss their discovery in Quanta Mag…

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. This has been announced at the presentation of the honoured proposals in The Hague…

We study the dynamics of individual emitters in micro cavities.

Tic tac toe, but with quantum effects. That makes learning the principles of quantum technology a piece of cake. This is the aim of a new start-up founded by researcher Evert van Nieuwenburg: QuantumPlayed. ‘Quantum is all around us and everyone should be able to learn about it.’

Friday afternoon, 1 October. Location: one of the most vibration-free places in the world. In this setting, Leiden top scientists launched Quantum Leiden. For decades, researchers at the Faculty of Science have been investigating quantum technology at the highest level and also have been brainstorming…

Promotores: H.W. Lenstra, K. Belabas (University of Bordeaux)

Artificial intelligence algorithms govern in subtle, yet fundamental ways, the way we live and are transforming our societies. The promise of efficient, low‐cost or ‘neutral’ solutions harnessing the potential of big data has led public bodies to adopt algorithmic systems in the provision of public…

In this thesis we present several methods to automate tomographic reconstruction algorithms and several novel tomographic reconstruction algorithms with the focus on being easily applicable and efficient to use.

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’.

An international collaboration, including Leiden physicist and computer scientist Vedran Dunjko, showed that quantum technology can speed-up the learning process of artificial intelligence (AI). To prove this, the physicists and computer scientists used a quantum processor for single photons. Their…

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

The worldwide race to the quantum computer is in full swing. This computer can take on computing tasks that we can only dream of today, such as finding proteins that can be used as medicines in seconds flat. Leiden physicists have discovered how the Majorana particle can be used as a building block…

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 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.

Science, Leiden Institute of Advanced Computer Science (LIACS)

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.