On February 19, 2025, Microsoft announced Majorana 1, the world’s first quantum processor based on topological qubits.

This represents a significant step toward creating quantum computers capable of solving large-scale industrial problems sooner than expected.

Majorana 1 is a quantum processing unit (QPU) powered by an architecture called “Topological Core.” This is based on a new material called a topoconductor, which combines indium, arsenic, and aluminum to create a topological state of matter. This state enables the creation and control of Majorana particles, used to form more stable and scalable qubits.

Microsoft’s goal is to integrate up to one million qubits on a single palm-sized chip, making quantum computers capable of tackling complex problems such as factoring large numbers for decrypting encrypted messages, molecular modeling, or creating self-repairing materials.

Previous Microsoft Announcements on the Project

In previous years, Microsoft has made several announcements regarding its commitment to quantum computing:

• 2017: During the Ignite conference, Microsoft discussed using topological qubits as the foundation for its future quantum computers.

• 2022: Microsoft announced the creation of the first topoconductor, a key material for creating stable topological qubits.

• 2024: The company demonstrated the ability to observe and control Majorana particles, a crucial step toward building practical topological qubits.

Additionally, in 2018, the company published an article in Nature claiming to have observed “Majorana quantized conductance,” a key phenomenon for creating topological qubits. However, in 2021, this article was retracted due to inconclusive data, raising doubts about the validity of the initial results.

Topological Qubit: What It Is and How It Works

A topological qubit is a type of qubit that uses the topological properties of matter to store and manipulate quantum information more robustly than conventional qubits. This robustness comes from protecting quantum information from local disturbances and decoherence, a key problem in current quantum computers.

The basic idea is to use “non-local quantum states” to store information, thus reducing sensitivity to perturbations from the surrounding environment.

To understand how topological qubits work, it’s necessary to delve into some basic concepts of quantum physics and condensed matter theory (the study of interactions between large numbers of particles that give rise to collective properties that cannot be explained through the study of individual particles).

For example, the study of electrical conductivity, resistance, and crystal structures in liquids and solids, or electricity without resistance (below a certain temperature) in superconductors, Bose-Einstein condensates, as well as topological materials of interest to us, which possess special electrical properties derived from their internal geometric structure.

One of the fundamental aspects of topological qubits is the use of particles called non-abelian anyons (not to be confused with the term anions referring to atoms with negative charge), which emerge in two-dimensional systems.

While fermions and bosons follow Fermi-Dirac statistics with the Pauli exclusion principle and Bose-Einstein statistics with the possibility of occupying the same quantum state respectively, anyons follow an intermediate statistics (hence “any”) between bosons and fermions and have a peculiar property: the exchange (braiding) between two anyons modifies the quantum state of the system in a “non-trivial” and irreversible way.

Anyons can be abelian or non-abelian, depending on how their quantum state changes when they are exchanged (ref. concept of quantum exchange).

The term abelian derives from the property of algebraic groups. A group is defined as abelian if it observes the commutative property, meaning given a pair of elements a and b, a · b = b · a holds. If this property is not satisfied, the group is defined as non-abelian.

In the exchange of two abelian anyons, the quantum state of the system changes in a simple and predictable way, while in the case of exchange (braiding since the exchange can be represented as an interweaving of paths in spacetime) of two non-abelian anyons, the system is transformed in a non-trivial way, modifying the quantum state in a complex manner to interweave quantum states non-commutatively.

And this is where our great countryman Ettore Majorana comes into play, since among non-abelian anyons are the Majorana fermions, those quasi-particles that behave like their anti-particles (thus if two Majorana fermions meet they annihilate), theorized in 1937 by our Ettore and experimentally observed in some condensed matter systems such as topological superconductors.

The unique combination of physical properties and topological characteristics such as non-locality, non-abelian statistics, and topological protection, make these quasi-particles ideal for applications in topological quantum computing.

Implementation of QuBits with Majorana fermions

Majorana quasi-particles, called Majorana zero modes (MZMs) because they have almost zero energy, have been detected at the ends of a topological superconducting nanowire subjected to a strong magnetic field.

If we exchange two non-abelian anyons, therefore two Majorana quasi-particles, through a braiding process, the quantum state of the system changes in a complex but predictable way.

For example, if the particles are exchanged once, the system changes according to a known transformation, while if they are exchanged multiple times in different orders, the final result depends on the sequence of exchanges.

However, the result is not random but follows a precise logic defined by the mathematics of topology. Think, for example, of a 3D commutation where if you make three consecutive movements 1-2-3 you will have a certain result, but if you make the movements in a different order 1-3-2 the result will not be the same (e.g., Rubik’s cube).

Exchanging two Majorana fermions in a superconductor as described above corresponds to a braiding operation and is performed by physically exchanging their positions.

This operation, as previously explained, changes the quantum state of the system in a non-commutative way and can therefore be used to implement quantum logic gates defined as gates.

A QuBit could therefore be created using two Majorana fermions at the ends of a filament and using the braiding operation for quantum gates.

The implementation process would be much simpler and more manageable than current methods used for QuBit creation.

Additional advantages would also come from error resistance provided by topological protection, stable manipulation without the need for correction (given by braiding), and scalability, as it would be sufficient to replicate the single filament to increase the number of QuBits.

However, there are currently technological limitations preventing practical implementation, due to the extreme difficulty in measuring Majorana fermions, which have not yet been definitively observed, as well as the technical complexity of their manipulation.

Microsoft is investing heavily in this research, paving the way for one of the most promising technologies for creating stable and reliable quantum computers that would lead to an unparalleled evolution in the world of computational processing, such that it could be considered a technological singularity.

Unfortunately, today, everything remains still experimental and the timeframes for the possible practical implementation of a quantum computer based on this technology are still far off, but it will be interesting to follow its developments and how Microsoft itself will manage to overcome current limitations.