The central processing unit is central to all computers and this rests upon semiconductor technology In a breakthrough, researchers from the group of Menno Veldhorst at QuTech has demonstrated that advances in technology can be used to build a two-dimensional array of qubits, designed to function as a quantum processor. This is considered to be a milestone for scalable quantum technology. The research has been published in the science journal Nature (“A four-qubit germanium quantum processor”).
Quantum computers have the potential to address complex problems. The primitive quantum devices around now can hold tens of qubits (the qubit is the starting block of quantum technology). However, a true quantum computer will need to be composed of millions or billions of qubits.
To help this to happen, the concept of quantum dot qubits is seen as being the answer for providing a scalable approach since they can be defined using standard semiconductor manufacturing techniques.
This has been demonstrated through placing four qubits into a two-by-two grid. This was sufficient to outline a universal approach to the control over all qubits. Researchers were also able to demonstrate how to operate a quantum circuit capable of entangling all qubits.
While there has been research progress to date, scaling beyond two-qubit logic has been challenging. To make progressTo break this barrier, the researchers began to work with missing electrons in germanium. This enabled electrodes, which act to needed to define qubits, to also control and entangle them.
Four qubits do not make for a universal quantum computer. However, by learning how to control qubits, the scientists have made a leap forwards towards true quantum computing and the realization of a dense, and extended, two-dimensional semiconductor qubit grid.
