​An ordinary bit has two states, 0 and 1. A quantum bit, or qubit, allows the superposition of these two states. Currently, researchers are investigating several types of qubits that are fundamentally very different. Leti’s qubit uses a charge’s spin state to expand the range of coding possibilities.

The INAC and Leti researchers working on the project trapped a charge in a "box" and precision-controlled the charge’s spin. One of the strengths of the approach they used is the nature of the "box." It is similar to a traditional MOS transistor measured at very low temperature. "We managed to make a single functional qubit in the lab. It was able to store, modify, and read quantum information," said one of the researchers.

The fact that the qubit was built using proven silicon CMOS processes is perhaps the main advantage. As the initial results were encouraging, the next step will be to show whether the approach can be used to build several qubits, couple them, and make them work together. Quantum computing is not yet within reach, but this research is a major advance.