Delft Spinoza Prize winner has remarkable plans

He made the world's first quantum mechanical calculation. Lieven Vandersypen will receive the Spinoza Prize this year to pave the way for quantum computers. “I find people who throw fabrications out there in the world hard to deal with.”

If you had asked him 10 or 15 years ago when the first quantum computer would finally emerge from the lab, the Professor in Quantum Nanosciences would have reluctantly said that it may never happen. “We were always clear that it was ongoing research and that the quantum computer may never be feasible,” Lieven Vandersypen said in 2007 when he was just named the Antoni van Leeuwenhoek teacher.

Not everybody appreciated his saying that, nut Vandersypen stuck to his guns. His electrons on gallium arsenide chips would simply not cooperate.

Ten years later, things are different. Vandersypen, now Scientific Director of QuTech (an alliance between TU Delft and TNO in the area of quantum technology), changed to silicon chips. A trio of articles about the wondrous behaviour of electrons on these chips followed in journals such as Nature and Science. The electrons only stayed on the gallium arsenide for 10 nano seconds. Just try doing calculations in that time. But now, on silicon, they can be managed 10,000 times longer. “Our research has really taken off,” says the Professor.

This did not go unnoticed by the Dutch Research Council (NWO). This year, the science funder awarded one of the four Spinoza Prizes – also known as ‘the Dutch Nobel Prizes’ – to the Professor at TU Delft. He will be awarded EUR 2.5 million to spend on science as he sees fit.

Lieven Vandersypen is looking for initiatives he can support to get girls to choose science studies more often.

Congratulations. You need to pave the way for the quantum computer. Does it feel like a burden?

“No. I’m pleased with the recognition. It is carte blanche to get on with things. I do not need to look for funds for every new idea and wait for months for the decision, but can now hire people and buy equipment as I see fit. I do not feel under any pressure. I have been researching quantum calculations for 25 years and this has brought me to where I am today. I am doing my best. I can’t do more than that.”

Even while working on his PhD research, Vandersypen achieved a first in the world when he used the spins of atom nuclei in molecules as qubits and, using seven of these qubits, was able to divide the number 15 in the determinants three and five. In doing so, he proved that using qubits in calculations was not only theoretical, but could also be used in practice.


What is the current status of the technique? In your latest articles you talked about ‘a programmable two-qubit quantum processor in silicon’. So two qubits?

“We are now working with more bits than that and we have improved the methodology to scale up. I can’t say how many bits. We hope to publish the information soon. Some journals ask you not to publish your findings elsewhere first.

But just as important, we have managed to get much better control over the electrons. This is very important if you want to use them to carry out calculations. The spins need to dance for you. I am the choreographer who decides the cadance.”


That is a good analogy to explain a technology that many people find incomprehensible. A technology of which the promise – the quantum computer – is also surrounded by so much uncertainty. Do you ever struggle with this yourself?

“It is hard sometimes. My wife is a doctor. She helps people every day and gets feedback immediately. I do get feedback from students of course, but from research? It is not yet clear what it will bring society. We have a very long-term focus.”


You may use the money from the Spinoza Prize as you see fit, as long as it is used to further science. You mentioned that you wanted to hire people and buy equipment. Are there any other plans?

“There is something else close to my heart. Girls and young women rarely choose scientific studies like physics or technical studies, even if they have an inherent interest in these. Something puts them off, perhaps a certain image. I also think that girls often underestimate themselves. I recently overheard a conversation among some female students who had been accepted for an honours programme (a special programme for highly talented students, Eds.). They doubted whether they were good enough. You seldom hear boys expressing their doubts. I am looking for initiatives in which I can support more girls to choose subjects such as physics.”

“And another thing is that I would like more people to learn to distinguish between fabrications and scientifically supported claims.”

Can you explain what you mean?

“We are facing big challenges in terms of climate, energy and health. I respect people who wonder if they should have the vaccine as they are scared that it may affect their health. But I find people who throw fabrications out there in the world hard to deal with. Information needs to be right. Of course issues are seldom black or white in science. Scientists often disagree with each other. But the discussions that they engage in are different. The way in which societal discussions are carried out is undermining democracy. I would like to see if it would be possible to design teaching materials for primary school that would equip teachers to deal with this issue and prepare children.”

Do you have any final tips?

“I would suggest to anyone interested in quantum calculating to log in on our quantum system via quantuminspire.com.”

Is it a simultator that shows you how quantum calculations works?

“No, it is a real quantum computer. Well, a prototype of one. We have a system with some qubits that act like quantum bits in a real quantum computer. It follows the same principles and you can do simple calculations with it. We have them here in two refrigeration systems in a lab. We are not using them for our research and they are intended solely for people who want to experiment with them.”

Qubits

The qubits with which Vandersypen and his colleagues are working consist of individual electrons that are kept in silicon enclosed by electrodes. Using magnetic and electrical fields, the researchers can control the spin of the particles. As with transistors on chips in current computers, it should be possible to couple qubits together on a chip.

The major advantage is that, unlike the normal bit that only has two separate states, zero or one, the quantum bit (or qubit) can be zero and one simultaneously. This is called superposition – a privilege of quantum mechanics – the electron spin can be left and right at the same time. So three qubits can thus consist of two to the third (2x2x2) eight quantum states at the same time. And 10 qubits can handle two to the tenth, or 1,024 simultaneous states. A quantum computer should be able to carry out simultaneous calculations in all different combinations.

The hope is that quantum computers will thus be able to solve complicated calculations that are too complicated even for the best super computers, such as calculating the properties of molecules and materials.

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