What is the topological state, the fourth state of matter that Microsoft is said to have achieved?

Microsoft has announced a major breakthrough in the development of quantum computing with the introduction of its Majorana 1 chip , based on topological superconductivity.

This device uses particles called Majorana fermions to improve the stability of quantum qubits, significantly reducing errors and external interference. The key to this progress lies in the exploitation of an exotic state of matter known as a topological state.

The topological state of matter has captured the interest of scientists and technologists for its unique properties, which could revolutionize not only quantum computing, but also electronics and materials physics. But what exactly is this state and why is it so important?

The concept of a topological state of matter comes from topology, a branch of mathematics that studies the properties of objects that remain unchanged under continuous deformations, such as stretching or twisting, as long as they do not break or fuse. In materials physics, topology describes how certain electronic properties can be robust to perturbations or impurities.

A material in a topological state has a key characteristic: while its interior behaves as an insulator, its edges or surfaces can conduct electricity without resistance. This peculiarity is due to the electronic structure of the material, which protects the edge states against external disturbances, guaranteeing stable and highly efficient conduction.

The study of topological states of matter received a major boost in 2016, when physicists David Thouless, Duncan Haldane and Michael Kosterlitz were awarded the Nobel Prize in Physics for their research on topological phase transitions. Their findings helped to understand how certain phases of matter can appear under extreme conditions, such as temperatures close to absolute zero.

One of the most notable phenomena in this field is the quantum Hall effect, in which a metal foil exposed to a magnetic field at extremely low temperatures displays quantized electrical conductance at its edges, while its interior remains insulating. This phenomenon has been fundamental to the development of advanced electronic devices.

Quantum computing has the potential to solve problems that would be intractable for conventional computers. However, one of its main challenges is the stability of qubits, as they are extremely sensitive to external disturbances that can cause errors in calculations.

This is where topological states play a crucial role. Topological superconductivity, such as that used in Microsoft’s Majorana 1 chip, combines the ability of certain materials to conduct electricity without resistance with the robustness of topological states. As a result, qubits generated in this state are inherently more stable and less prone to loss of quantum coherence.

Microsoft has successfully fabricated topological superconducting nanowires that operate at temperatures close to absolute zero, representing an important step toward creating practical and scalable quantum computers.

The discovery and application of the topological state of matter opens up new opportunities in multiple areas, from electronics to quantum computing. With companies like Microsoft betting on this technology, the future of quantum computing looks brighter than ever. As research progresses, we are likely to see surprising new applications of this state of matter in the coming years.