Koen Groenland

About me

I work as a quantum innovation officer at the University of Amsterdam and QuSoft. I accelerate the development of valuable quantum technology by connecting companies to academic research. Many of our valorisation activities are done through the network hub Quantum.Amsterdam, for which I am the main coordinator. 

I am also involved in scientific research on quantum computers. In my work, we find input signals (like electric waves or laser pulses) that make a quantum computers perform a desired operation on quantum data. Examples are shuttling information from one part of the computer to another, or executing the quantum-version of certain logical gates like AND and OR.   READ MORE >


Succesful Science & Innovation dinner on 'Quantum'

Nov 2023

We occasionally host community event for our network of the Netherlands most prominent leaders in Quantum Tech. This fall, this was in the form of a Science & Innovation dinner where over 30 experts discussed the current state of affairs. 

See the 'aftermovie': https://www.linkedin.com/posts/amsterdamsciencepark_watch-the-aftermovie-activity-7128394792270454785-EgZL

289 high-school students follow the Quantum Quest

Nov 2023

This November, the Quantum Quest kicks off with more participants than ever: a whopping 289 students from over 100 different schools will start a journey to learn the fascinating math behind Quantum Computers. That's an impressive number, considering that this is arguably the hardest challenge that high school students will come across -- most of them doing this in spare time! But hopefully worth every minute ;)

This year, we worked hard to make the materials more accessible, with great mini-video's and a subdivision of students in smaller 'Houses' that make it easier to talk to peers. 

More information: www.quantum-quest.org

Executive course Introduction to Quantum Computing

Nov 2023

After a successful previous edition, we're organising another course Introduction to Quantum Computing, focused on opportunities and threats for businesses. That's a powerful collaboration between the techies from Quantum.Amsterdam and the real-world impact perspective from University of Amsterdam - Amsterdam Business School. It's aimed specifically at those who make strategic decisions in IT, machine learning or cybersecurity.

📅 Tue 28 + Wed 29 November 2023

⏰ 14:00 - 18:00

📍 Startup Village Amsterdam

>> More information: abs.uva.nl/quantum-computing 

I believe we can proudly say that we brought together the most prominent thought leaders in the Netherlands around Quantum Tech, who will share their insights on how we can optimally deal with this disrupting innovation:

Harry Buhrman | Deborah Nas | Frank Phillipson | Mario Dagrada | Marc Salomon | Dr. Martijn Dekker | Julian van Velzen | Camille de Valk | Alexander Urech | Koen Leijnse

Meet me here in Summer 2023:

Apr 2023

Masterclass Quantum for high school students

Dec 2022

In January and February, we're organizing another Masterclass Quantum for Dutch high-school students (5-6 VWO). For more information, see: https://www.betapartners.nl/masterclass-quantum2023/ 

Masterclass for business: Introduction to Quantum Technology

July 2022

On 24 November and 1 December, we organise a Masterclass that forms an introduction to the Business Cases for Quantum Computing. This is a collaboration between Quantum.Amsterdam and the Amsterdam Business School. Our aim is to provide an accessible yet deeply educative experience to managers, IT professionals, innovation experts and policy makers. No prior knowledge needed!

We can be proud to have a team of the most distinguished professors and business leaders that can be found within the Netherlands, which together cover the whole width of Quantum Technologies: from computing to sensors to crypto, and from the fundamental aspects to tomorrow's corporate usage.

To see more information and to sign up, see here:


Update to Professional's Guide to Quantum Technology

May 2022

Some major updates have been included in our free, online guide that should help journalists, managers, and IT professionals understand the impact of quantum in the real world. Check out Chapter 3 and 5 on the Quantum.Amsterdam website

Professional's Guide to Quantum Technology

January 2022

Together with Joran van Apeldoorn, I'm writing a free, online guide that should help journalists, managers, and IT professionals understand the impact of quantum in the real world. As of today, it's steadily expanding -- you can start reading on the Quantum.Amsterdam website

Available MSc student project: A Quantum Benchmarking tool

December 2021

Benchmarks are used to compare the speeds of computers. For quantum computers, no standardized benchmarks exist yet, but it's up to you to invent and implement one. There are several challenges: all quantum computers work differently, and perhaps one computer excells at a certain task, whereas another performs best on a completely different task. What is a representative test that allows us to compare widely varying pieces of hardware?


Are you interested? Then let's further discuss this with a cup of coffee! Contact me at k.l.groenland@uva.nl.
(This project is open until removed from this webpage). 

Masterclass for High Shool students in January/February

December 2021

Only available in Dutch:

Are you a smart high-school student in 5-6 VWO, and would you like to learn about the cutting edge of Quantum Computers and Quantum Field Theory?  (Or do you know one?) During this 3-day masterclass, you will take lectures at the University of Amsterdam and learn all about these fascinating topics:


Quantum Quest 2021 has started!

November 2021

The Quantum Quest is a free online webclass for students in the last years of high school (~16-20 years old). During a 5-week program, we dive into the mathematics behind quantum computing, going through probabilistic bits, quantum bits, unitary operations, and elementary algorithms and protocols (like Teleportation and Grover's search). To make the material sufficiently accessible, we omit complex numbers and work only with reals (and surprisingly, quantum computers still work fine!).
The course is extremely challenging and aiming at the best-of-class students. This year, we  opened  up submissions to anyone in the world, and  have a very international audience (note the peak in Africa, especially Ghana, thanks to our collaboration with AIMS):

Signups for 2021 have closed... but if you're interested in participating:

More in-depth testing of N-qubit gates

May 2021

Juan Diego Arias Espinoza performed an extensive numerical analysis that our proposed method to perform an important gate, the Toffoli gate, performs very well on Trapped Ion computers. However, some clever tricks were needed to get the fidelities up to competitive levels. The result was recently published in PRA in the paper "High-fidelity method for a single-step N -bit Toffoli gate in trapped ions".

PhD defense ceremony

January 2020

On the 17th of January 2020 I defended my PhD thesis. The thesis is freely available online (link), and the fully open-source LaTeX code can be found on github

Efficient circuits for Trapped Ion quantum computers

January 2020

We find a striking connection between the physics of quantum computers that use trapped ions, and the emerging field of quantum signal processing. This allows us to perform difficult quantum gates in less steps, relying only on the most simple entangling operation a trapped ion computer can perform. 

(Update July 2020) This result is now published as follows:

 Koen Groenland, Freek Witteveen, Kareljan Schoutens, Rene Gerritsma, Signal processing techniques for efficient compilation of controlled rotations in trapped ions, New Journal of Physics, Volume 22 (2020)

Difficult quantum gates can be performed in a single step

November 2019

Together with Stig Rasmussen and Nikolaj Zinner from Aarhus University, we find that the notoriously hard Toffoli quantum gate can be performed using a surprisingly simple protocol. We require an all-to-all Ising type interaction between the qubits, and a resonant field on a single special qubit. After throwing away the special qubit, a Toffoli occurred on the remaining qubits. 

(Update Februari 2020) This result is now published as:

S. E. Rasmussen, KG, R. Gerritsma, K. Schoutens, N. T. Zinner, Single-step implementation of high fidelity n-bit Toffoli gates, Phys. Rev. A 101, 022308 (2020) (without paywall: arXiv:1911.07548)

Popular state transfer protocols now work in more cases

September 2019

Certain experimental protocols, named with acronyms STIRAP or CTAP, turn out to work on many more systems than was previously known. We find that they naturally generalize to bipartite graphs. 

KG, Carla Groenalnd, Reinier Kramer, Adiabatic transfer of amplitude using STIRAP-like protocols generalizes to many bipartite graphs, Journal of Mathematical Physics 61, 072201 (2020);   arXiv:1904.09915 

Transferring a quantum state over a network of coupled spins

January 2019

With the advent of advanced quantum information processing, it is of increasing importance to transport quantum information over a physical medium (think of a wire, or a network of wires). We consider the case where the information is encoded in a spin degree of freedom (think of an electron whose "rotation axis" can point either up or down), and the medium is made up of spins that are all pinned in place. 

It turns out that the repulsive forces between the spins can be used to delocalize the information over the whole network, and then localize it again at some other place. This was known for mediums that form a perfect line. I generalize this to more general configurations, finding that information can be sent over many networks that look like a bipartite graph. 

My article is planned for publication in SciPost Physics (DOI: 10.21468/scipostphys.6.1.011)

Many-body strategies for multi-qubit gates

April 2018

Quantum computers, just like their classical counterparts, may use a universal gate set consisting of local gates, in order to approximate any possible operation on it's qubits. Typically, one chooses a two-qubit gate such as the CNOT together with a set of single-qubit gates. 

However, we asked ourselves the question: If N qubits are coupled by some interaction of our choice, can we construct interesting gates that act on all qubits at the same time? 

For this to work, we look at the so-called Krawtchouk chain, which is special because all of it's eigenvalues are integer numbers. Because this system is well understood, we can apply condensed-matter many-body techniques, resulting in two surprising new contributions:

Our article was recently published in PRA (https://journals.aps.org/pra/abstract/10.1103/PhysRevA.97.042321). Find the version without paywall at ArXiv or my GDrive.