(HPC.Wire) The French company Leti CEA-Leti makes giant wafers full of devices, and, after measuring, researchers at the Niels Bohr Institute, University of Copenhagen, have found these industrially produced devices to be suitable as a qubit platform capable of moving to the second dimension, a significant step for a working quantum computer.
One of the key features of the devices is the two-dimensional array of quantum dot. Or more precisely, a two by two lattice of quantum dots. “What we have shown is that we can realize single electron control in every 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”, says Fabio Ansaloni, former PhD student, now postdoc at center for Quantum Devices, NBI.
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 result realized at the Niels Bohr Institute shows that it is now possible to control single electrons, and perform the experiment in the absence of a magnetic field. So the next step will be to look for spins – spin signatures – in the presence of a magnetic field. This will be essential to implement single and two qubit gates between the single qubits in the array. Theory has shown that a handful of single and two qubit gates, called a complete set of quantum gates, are enough to enable universal quantum computation.