search.noResults

search.searching

saml.title
dataCollection.invalidEmail
note.createNoteMessage

search.noResults

search.searching

orderForm.title

orderForm.productCode
orderForm.description
orderForm.quantity
orderForm.itemPrice
orderForm.price
orderForm.totalPrice
orderForm.deliveryDetails.billingAddress
orderForm.deliveryDetails.deliveryAddress
orderForm.noItems
HIGH PERFORMANCE COMPUTING


Quantum development ramps up


KEY BREAKTHROUGHS AND NEW SOFTWARE ENVIRONMENTS ARE HELPING DRIVE DEVELOPMENT OF QUANTUM COMPUTING FOR SCIENTIFIC RESEARCH AND INDUSTRIAL USE


Researchers at the Niels Bohr Institute are working to overcome obstacles in developing a working


quantum computer, as part of a pan- European collaboration with French microelectronics developer CEA-Leti. The collaboration aims to explore the


use of transistors as qubits, and has demonstrated the development of a two- dimensional array which helps to improve error correction in this new device. One obstacle on the path to create a


working quantum computer has been the development of qubits. Previously these have only been produced by universities and in small numbers. However, researchers at the Niels Bohr Institute, University of Copenhagen, found that they could use CEA-Leti wafers. These industrially-produced devices were found suitable as a platform for a two- dimensional array of qubits – a significant step for a working quantum computer. The results of the study are in Nature Communications. One of the key features of the devices is the 2D array of quantum dots. Or more precisely, a two-by-two lattice of quantum dots. Dr Fabio Ansaloni, a postdoc at the Center for Quantum Devices at NBI, said: ‘What we have shown is that we can realise single electron control in every


4 Scientific Computing World Winter 2021


single one of these quantum dots. This is very important for the development of a qubit, because one of the possible ways of making qubits is to use the spin of a single electron. So reaching this goal of controlling the single electrons and doing it in a 2D array of quantum dots was very important for us.’


Industry collaboration leads to an important quantum milestone The paper, authored by Ansaloni and his colleagues, states: ‘We demonstrate single-electron occupations in all four quantum dots of a two-by-two split- gate silicon device fabricated entirely by 300mm-wafer foundry processes. By applying gate-voltage pulses while


performing high-frequency reflectometry off one gate electrode, we perform single-electron operations within the array that demonstrate single-shot detection of electron tunnelling and an overall adjustability of tunnelling times by a global top gate electrode. Lastly, we use the two- dimensional aspect of the quantum dot array to exchange two electrons by spatial permutation, which may find applications in permutation-based quantum algorithms.’ Using electron spins has proven to be


advantageous for the implementation of qubits. In fact, their ‘quiet’ nature makes spins weakly interacting with the noisy environment, an important requirement to obtain highly-performing qubits. Extending quantum computers processors to the second dimension has been proven to be essential for a more efficient implementation of quantum error correction routines. Quantum error correction will enable future quantum computers to be fault-tolerant against


individual qubit failures during the computations.


The importance of industry-scale production Anasua Chatterjee, assistant professor at the NBI centre, adds: ‘The original idea was to make an array of spin qubits, get down to single electrons and become able to control them and move them around. In that sense, it is really great that Leti was able to deliver the samples we have used, which in turn made it possible for us to attain this result. ‘A lot of credit goes to the pan-European project consortium, and generous funding


“Vital for the development of a qubit, because one of the possible ways of making qubits is to use the spin of a single electron”


@scwmagazine | www.scientific-computing.com


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34