One of the groundbreaking achievements of mankind in the past century is certainly the invention of computer and the advances in the field of information processing. It enabled any kind of data to be stored, manipulated and shared in many ways allowing for a boost in technology as well as in fundamental science. Even though being virtually absent in our daily lives two decades ago, today information processing is an integral part of human civilization, a fact that also underlines the significance of the advances in this field in recent years. Thus, in fundamental research, exploring novel means to improve the performance of computers is a very active topic and will likely to remain such in the foreseeable future.

A significant leap forward in information processing is being able to use quantum mechanical laws for data storage and calculation, the laws which are valid for microscopic objects and very low temperatures but unfortunately not for the world we perceive - the ambient conditions. Yet, there has been increasing laboratory efforts to exploit quantum superposition in data processing, a principle in quantum mechanics allowing for faster and resource-efficient storage and processing superior to the classical computers we have today, and scientists are continuously taking steps to realize a quantum computer which could be made use of outside laboratories.

A critical drawback of these potential quantum processors, however, is their sensitivity to operating conditions which can not be controlled perfectly even by state of the art experimental techniques. Although there are various approaches to realize a quantum computer using different materials and different architectures, each of them suffers from this drawback: one can do computation or store data only for a very short time before everything gets destroyed by coupling to the environment. A theoretical proposal aiming to eliminate this challenge focuses on using the topological phase of a physical system which is tolerant to the changes/imperfections in operating conditions causing the faults. The topological phase can be envisaged as a rubber ball having no holes in its shape: even though one can deform it, say by kicking or squeezing it, it will stay as a ball and will not be, say a doughnut having one hole in its shape. In this case, a doughnut and a ball are in different topological phases. Accordingly, by using the topology of a physical system to compute and to store data, one can implement fault-tolerant quantum information processing.

We use nanowires, tiny conductive wires thousand times thinner than a hair, and bring them in contact with a superconductor to realize a unique topological phase of matter so as to prove it useful as a building block for topological (fault-tolerant) quantum information processing. Using the right materials and fine-tuning the electric and magnetic fields, we find the sweet spot exhibiting the topological protection. This topologically protected phase supports the so-called Majorana fermions (exotic particles somewhat similar to the electrons in a solid) in a nanowire-superconductor hybrid system. We try to measure and manipulate these Majorana fermions since controlled manipulation of Majorana fermions could pave the way for quantum computers sprawling out of the laboratories, replacing the computers we use today.