Majorana fermions are hypothetical particles that are their own antiparticles, first proposed by physicist Ettore Majorana in 1937. In condensed matter systems, quasi-particles behaving like Majorana fermions can emerge under specific conditions, such as in topological superconductors.
Why They Matter in Quantum Computing:
- Topological Protection: Majorana-based qubits are expected to be highly resistant to local noise and decoherence, thanks to their non-local encoding. This makes them ideal for topological quantum computing.
- Non-Abelian Statistics: When two Majorana particles are exchanged, the quantum state of the system changes in a way that depends on the order of the exchange — a property called non-Abelian braiding. This allows for fault-tolerant quantum gates.
- Qubit Construction: A single logical qubit can be built from a pair of spatially separated Majorana fermions, with the quantum information stored nonlocally across them.
While experimental evidence for Majorana fermions is still under investigation, their unique properties make them strong candidates for building robust, scalable quantum computers.