New-Tech Europe Magazine | Q3 2021 | Digital Edition

Electrical readout of electron-nuclear spins in a diamond quantum chip at room temperature

Milos Nesladek, IMEC

In short: Nuclear spins in diamonds are promising candidates for quantum technologies because of their long coherence times The key to diamond quantum applications is the nitrogen- vacancy center in the crystal that gives access to both nuclear and electron spins The team of Milos Nesladek in IMO-IMOMEC succeeded in the electrical readout of entangled nuclear-electron spins at room temperature This is important for device scaling and integration as well as applications such as ambient sensing The team of Milos Nesladek from IMO-IMOMEC, an imec research group at University of Hasselt, has a long track-record of using artificial diamonds in the race to develop the

best solid-state quantum system. In research that was recently published in Nature Communications they now demonstrate a viable approach for a quantum technology platform that operates at room-temperature via electrically-read electron-nuclear spin gates on a diamond electronic chip. This proof of concept is a first step towards more complex, electrically-read gates for advanced quantum technologies that can benefit from the long nuclear spin coherence in diamond. Nuclear and electron Semiconductor spin qubit systems are promising candidates for future quantum technologies, such as quantum computing, telecommunication and sensing because of their potential for wide spins in diamond quantum systems

electronic scalability and nanoscale device integration. Nuclear spins in diamonds are particularly interesting because of their large coherence times which is important for performance and reliability of complex quantum applications. At ambient temperatures the coherence time is in the range of seconds; when cooled down to around 10K it even increases to tens of minutes. Milos Nesladek: “Key to quantum applications for diamond is the nitrogen-vacancy (NV) center, a defect in the crystal where a nitrogen atom replaces one of the carbons adjacent to a free lattice space (a vacancy). The negatively charged NV center is one of the most attractive solid-state qubit platforms as it benefits from an electronic spin that can be used as a qubit or as an auxiliary qubit for reading dark nuclear spins. Having

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