In the previous modules we have discussed qubits realized with electron spins and superconducting circuits. Despite the differences in their hardware implementation, these platforms have something very important in common. The qubits are imperfect and subjected to noise. For example, fluctuations in magnetic fields can perturb an electron spin such that its phase is lost. This is why we need quantum error correction.

This week we will introduce you a completely new kind of qubit, which can potentially alleviate the need of quantum error correction in a future quantum computer. This qubit is based on a quasi-particle called Majorana fermion, which is halfway between being an electron and not being an electron. When you fuse two Majoranas together you end up having one or no electrons. The fact the that the information (having or not having an electron) is delocalized in two Majoranas far from each other, makes harder for the environment to perturb its state.

The promise of a qubit much less sensitive to noise than other implementations has attracted Microsoft’s interest. Check out this video to discover what is,  according to Microsoft, the path towards a scalable quantum system with Majoranas.

In the first three videos, Michael Wimmer will introduce the concept of topology and Majorana bound states. Attila Geresdi will then explain, in an other three videos, how we can realize quantum gates and in which kind of physical system we can find this new type of quasi-particles.