(PRNewsWire) According to recent theories, unique particles called “Majorana fermions” can protect their quantum states against external perturbations and thus could be used to build stable quantum computers, provided these particles can be achieved in solid materials. Thus, physicists have been looking for materials that emulate a “Kitaev honeycomb” (solid-state model known to birth Majorana fermions in magnetic fields). And, they have now succeeded—A study published in Nature Communications, led by Prof. Kwang-Yong Choi from Chung-Ang University, Korea, unveiled the existence of Majorana fermions in α-RuCl3, a graphene-like quantum magnetic material closely resembling a Kitaev honeycomb in a magnetic field. Prof. Choi says, “If we can realize perfect Majorana fermions in solid materials, a stable quantum computer is not far away!”
The properties of α-RuCl3 are such that at low magnetic fields, it exhibits a zigzag ordering of “spins”—an essential quantum property influencing the ordering of electrons in atoms and molecules. While in high magnetic fields, it exhibits a “spin polarized state,” with all its spins oriented along the field. For intermediate fields, however, an interesting phase emerges. Prof. Choi explains, “Based on experimental and theoretical considerations, two opposing viewpoints exist for the intermediate field phase, one invoking conventional multi-particle magnetic excitations and the other Majorana fermionic excitations. Our aim was to characterize excitations emerging in the intermediate-to-high field phase.”
These findings corroborate the viewpoint that the intermediate field phase in α-RuCl3 is due to Majorana fermionic excitations, establishing it as a Kitaev honeycomb material. Prof Choi is excited about the implications of their findings, as he concludes, “We are close to achieving an ideal Majorana fermion through deconfinement of bound Majorana particles by strain engineering. We will now attempt to fine-tune magnetic parameters and stabilize the fragile Majorana fermions through interface engineering. In addition, we will test their statistics as a first step towards building quantum bits!”

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