A prison for ions and cold atoms for a unique quantum simulator? Checking the geographical position of a bank computer with quantum verification? Quantum optics to see if a communication network has been tampered with? These are three of 16 futuristic projects within the National Growth Fund programme Quantum Technology organised by Quantum Delta NL in collaboration with NWO. In total, more than €5.3 million is involved.

A special feature of this call is that PhD researchers could apply for a personal research budget, this strengthens the basis for the Netherlands’ leading position in quantum research.

Of the sixteen projects awarded, four are from such newly promoted researchers. Also, four of the 16 applicants awarded are women. Both numbers are relatively high, but there is work to be done. Quantum Delta NL is dedicated to achieving a better gender balance.

In 2023, a new similar call will be opened in collaboration between Quantum Delta NL and NWO.

Quantum technology is a key technology that can provide answers to many unsolved societal challenges. The central government is putting 615 million euros into this pioneering technology. Of this, within the Quantum Technology programme, a total of 42 million euros has been set aside for scientific research and innovation, over a duration of seven years.

An Integrated Quantum Circuit
F. Borsoi –TU Delft

Within the project, the researcher will apply classical electronic architectures on infant quantum dot devices to solve qubit control and interconnectivity bottlenecks. In the route from a few to a million qubits system, this will result in a modular building block for semiconductor quantum computers and simulators.

(NGF.1582.22.001: Sensing of modular semiconductor qubit arrays from the inside)

Using regular computers for predicting and reducing the influence of noise in quantum computers
T.J. Coopmans – Leiden University

Noise in quantum computers is the main hurdle for them to outperform their regular (classical) counterparts. The researchers first propose to develop a novel method for simulating noisy quantum computers on classical computers. Next, they will use the new method for better predicting and reducing the influence of noise on the performance of near-term quantum computers.

(NGF.1582.22.035: Robust decision-diagram simulation for noisy quantum circuit analysis)

Quantum revolution will be automatized
O. Danaci – Leiden University

Noisy small-scale quantum computers are here, and fault-tolerant ones on the horizon. However, the current effort is limited to table-top experiments in university labs overflowing into prototype hardware; not an industrial, automated effort. The calibration and control problem is a fundamental tenet of quantum advantage. Yet, tune-up of even the basic building blocks take hours of experts, and needs to be done repeatedly. Inspired by the success in AI-driven experiments in other fields, MAZeLTof-Q promises to deliver not only automation of the calibration for fresh out of assembly-line quantum hardware, but also performance-levels ushering fault-tolerance era.

(NGF.1582.22.031: MAZeLTof-Q, Machine Assisted Zero-Knowledge Tune-up of Superconducting Qubits)

Digital-analog quantum computing: a win-win situation
E. Greplova – TU Delft

Quantum computing is often limited by spurious interactions between the quantum bits on the quantum device, but in fact, quantum computing can be made easier by using this already-present native interactions to our advantage. In this proposal the researchers show that this hybrid approach leads to better computation accuracy and less engineering overhead. They propose how to design, evaluate and simulate these hybrid quantum computation models and how this framework may lead to new near-term applications for quantum computers.

(NGF.1582.22.026: Optimal Digital-Analog Quantum Circuits)

Experimental quantum position verification
W. Löffler – Leiden University

The geographic location often is an excellent credential, for instance, for the computer in the building of a bank. Unfortunately, secure verification of a position using triangulation has been proven to be impossible with classical communication. The goal of this proposal is to firstly demonstrate experimentally “quantum position verification”, which can be secure. By using qubits, the quantum mechanical no-cloning theorem guarantees that attackers cannot compromise the protocol by intercepting and copying the information. After a lab demonstrator and a field test, the researchers hope to be able to implement quantum position verification in the Dutch quantum network.

(NGF.1582.22.025: Experimental Quantum Position Verification)

Ion Jail for new quantum simulator
R.S. Lous – Eindhoven University of Technology

Ultracold atoms and trapped ions are at the forefront of quantum simulation, especially if you combine the two platforms. In quantum simulation, you build a well-controllable testbed in the laboratory with which you do research on quantum systems that aren’t easy to make. This proposal is about the design of a state-of-the-art ion trap (or jail) and the building thereof. With this ion trap the researchers build a unique quantum simulator. Theywill use the ion jail to probe the many-body aspects of the cold bath of atoms, where dipolar interactions play a role.

(NGF.1582.22.027: Design of ion trap setup for new quantum simulator (Dit))

Network Security via Quantum Sensing
prof. P.W.H. Pinkse – University of Twente

The researchers develop quantum-optical characterisation techniques to sniff out if a communication network is being tampered with, by checking optical fibre properties. In the same way they also check the area enclosed by a large fibre loop by measuring the subtle effect of the earth’s rotation on the light travelling in the loop.

(NGF.1582.22.023: Network Security via Quantum Sensing (NeSQuS))

How energy efficient can quantum computing be?
S.R.K. Rodriguez – Foundation for Dutch Scientific Research Institutes, AMOLF

Quantum computers are expected solve certain important problems much faster than classical computers. But could this quantum speed advantage come at the expense of an energy efficiency disadvantage? Researchers in this project will answer this question, theoretically and experimentally, using a novel optical platform. They will compare the minimum energy required to erase a quantum and a classical bit in finite time. The results will lay the foundations for understanding and optimizing the fundamental trade-off between energy efficiency, speed, and accuracy, in quantum operations.

(NGF.1582.22.011: The cost of erasing an optical qubit)

Trapped ions make excellent quantum bits
A. Safavi-Naini – University of Amsterdam

Trapped ions make excellent quantum bits. They can be controlled to form miniature quantum computers. However, scaling up the the system size while maintaining the quality of operations remains a formidable challenge. The researchers will employ optical tweezers and electric fields to boost the scalability and speed of the quantum computer. Their research will be an important step towards universal quantum computing.

(NGF.1582.22.030: Trapped-ions, electric fields, and optical tweezers: Ingredients for a novel quantum computer)

Detecting microwaves using quantum sensors in diamond
T. van der Sar – TU Delft

Atomic defects in diamond have emerged as powerful magnetic-field sensors. However, their sensitivity in the microwave regime – important for materials science, radar, and wireless communication – is limited. This research will interface a diamond sensor chip with a magnetic film that will enable the detection of microwaves by locally converting their frequency to a detectable range. The goal is to realize sensor chips with sensitivity in the 1-100 gigahertz range.

(NGF.1582.22.018: Broadband quantum sensing of microwaves using spins in diamond via magnetic frequency conversion)

Noisy quantum computers ‘under control’
O.T.C. Tse – Eindhoven University of Technology

Quantum computers are made up of many entities that, not only interact with each other but also with the outside world. These interactions give quantum computers the power they need to surpass classical  computers, but at the same time make them difficult to control due to a phenomenon called quantum decoherence, or in other words, noise. In this project, researchers develop noise-resistant algorithms, paving the way for currently available quantum computers to solve hard problems in cryptography, and to study chemical processes for the development of new materials and medicine more effectively than currently possible.

(NGF.1582.22.009: Variational Quantum Optimal Control on Rydberg-atom quantum processors)

Enhancing mechanical quantum sensors with flashes of light
prof. E. Verhagen – Foundation for Dutch Scientific Research Institutes, AMOLF

Mechanical resonators, especially tiny ones, are extremely sensitive sensors of a wide variety of signals: from accelerations to magnetic fields and molecular masses. This project investigates whether the performance of mechanical sensors can be improved by controlling the quantum state of a vibrating resonator. The researchers do so with the help of strong flashes of laser light, which induce special quantum fluctuations in the resonator that enhance its sensitivity to useful signals.

(NGF.1582.22.020: Enhancing nanomechanical sensing with quantum squeezing and entanglement)

Searching for the correct molecular mirror image
prof. L. Visscher – VU Amsterdam

The new Dutch quantum supercomputer will be put to the task of determining the correct molecular mirror image. Just like with people, we have that the mirror image of a molecule looks almost identical but still is crucially different: Imagine putting your right hand in a left-hand glove! For molecules, this may imply the difference between an effective drug and a potentially dangerous substance. The researchers in this project aim to develop a combination of measurement and quantum simulations which can unambiguously determine whether we have the desired molecule and not its mirror image.

Metal atoms in semiconductors go quantum-telecom
prof. C.H. van der Wal – University of Groningen

Quantum technology can make the internet more secure and provide better sensors. Much is still unknown about which materials are most suited for building such technology. This project builds on the recent discovery that adding individual metal atoms to a widely-used semiconductor material provides a quantum memory or sensor that can be set and read-out with the same colour of light that is used in the fibre-optics of the internet. The research aims to better understand which metal atoms are most suitable for this, and how they can be controlled inside a semiconductor device.
(NGF.1582.22.034: Telecom-compatible quantum emitters in SiC crystals: fundamentals of spin interactions and device engineering)

An ultrasensitive magnetic microscope based on a diamond quantum sensor
G. Welker – TU Delft

The researchers propose to develop a new type of microscope with extreme magnetic field sensitivity, 100 times better than current magnetic microscopes. The microscope will use a tiny crystal defect and an impurity in a diamond crystal as a magnetic field sensor. It is so sensitive because the researchers use a tin impurity instead of a nitrogen impurity, which is better protected from electric noise. Furthermore, they use an optical glass fiber to collect the light emitted from the tiny crystal defect more efficiently.

(NGF.1582.22.038: Nanoscale magnetic imaging using a fiber-coupled tin-vacancy spin in diamond)

Listening to Josephson junctions: do they contain new fundamental particles?
prof. F.A. Zwanenburg – University of Twente

The researchers look for signs of a special particle, the elusive Majorana-fermion, which promises to make a new noise-insensitive type of quantum computer possible. This strange particle is its own anti-particle and is therefore very hard to find. To create them, they combine ‘topological’ materials with superconducting contacts to create ‘Josephson junctions’ and cool down to ultralow temperatures. When they apply a small voltage, charges in the device start to vibrate and generate radiation like a tiny antenna. A Majorana will have a different frequency than normal electrons; by recording this radiation they measure whether their device contains these exotic particles.

(NGF.1582.22.039 – Sensing Josephson radiation using wideband high-frequency spectroscopy)