New-Tech Europe Magazine | Q3 2021 | Digital Edition

MilosNesladek:“Wenowsuccessfully demonstrated electrically-read entangled qubits. The next step is to leverage the scalability of the basic electron-nucleus unit and create arrays. We are working on a chip with 4 NV centers, 50nm apart. If we can stably couple these 4 qubits to 5 nuclear spins, we have access to a 20-qubit system which can be operated at reasonably low temperatures (around 10K or even higher). Then it becomes interesting for many new applications, such as quantum simulators!” Biography Milos Nesladek Prof. Milos Nesladek, PhD, obtained his MSc. degree from the Faculty of Mathematics and Physics, Charles University in Prague, and the PhD degree from the Czech Academic Sciences, in collaboration with KU Leuven in the field of electronic transport in semiconductors. He is a professor of physics at the University of Hasselt and a member of staff at IMO-IMOMEC, an imec research group at University of Hasselt. He is

one of the pioneering scientists in the field of growth of CVD diamond crystals in all forms, being in that field for the last 30 years. Prof. Nesladek’s research topic deals with photoconduction in condense matter systems with emphasis on wide-bandgap semiconductors. An example of this research is the development of photoelectrically read solid state Q-bits in diamond based on paramagnetic spin centres. Prof. Nesladek has participated in a large number of EU projects ranging from basic physics to industrial development projects which, some of them, he has coordinated. Prof. Nesladek is member of several conference boards and he is the Belgian representative to the Quantum Community Network (QCN) of the Quantum Flagship. Prof. Nesladek published over 300 scientific papers and contributed to several books. He is associated editor of Diamond Related Materials

electrical readout of a single nuclear spin of the NV center, mediated by a single electron spin,” says Milos Nesladek. “Moreover, we demonstrate this at room temperature. One of the advantages of these qubits is their ability to operate at ambient temperatures. The nuclear spin coherence time at these high temperatures is still in the range of seconds. For certain quantum operations, we will also cool it down to tens of Kelvins but not as much as in a classical system that targets temperatures close to absolute zero in the range of millikelvins. Enabling quantum operations at higher temperatures has an enormous impact on future quantum computer systems where the cooling systems consume a huge amount of energy and is currently one of the bottlenecks for scaling up.” Quantum applications and arrays “Diamond-based qubits are unbeatable as room-temperature sensors for example for magnetic/ electric field, temperature or molecules. If we do entanglement- based sensing, we can even further increase their sensitivity. For quantum computing applications, which typically require thousands of qubits, diamond qubits still face a few hurdles. The challenge is to deterministically produce NV centers with high probability. Currently, we can create them with a ~90% probability, but that number drops to ~65% when creating 4. If you go to thousands, the probability is very small… To solve this will require more research on all fronts, from materials to electronics to the full system.”

Prof. Milos Nesladek, PhD,

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