In 2025, a team of scientists from the Netherlands achieved a significant breakthrough in quantum technology, developing ultra-thin devices that function without bulky magnets and operate at room temperature. This discovery opens new horizons for creating compact, fast, and energy-efficient technologies.
The research, published in Nature Communications, confirmed the existence of the quantum spin Hall (QSH) effect in graphene without the need for an external magnetic field. This effect, related to the quantum mechanical property of electrons known as spin, allows for the transmission and processing of information using spintronic devices.
During the experiments, scientists used magnetic graphene, layering it with an antiferromagnetic material, CrPS₄. This combination altered the internal properties of graphene, leading to spin-orbital and exchange interactions, crucial for forming topologically protected edge states. These states ensure the movement of electrons along the edges of the material without resistance, with their spins aligned in opposite directions – this is the quantum spin Hall effect.
The creation of such devices previously faced significant challenges, as controlling electron spin required powerful magnetic fields and extremely low temperatures. However, the new research has demonstrated that magnetic properties can be created internally within the material, using the proximity effect with the antiferromagnetic CrPS₄. Researchers have also noted that the ability to observe stable spin states even at room temperature makes the technology more practical for real-world applications.
This breakthrough validates theoretical predictions made a decade ago, indicating that graphene, under specific conditions, can support stable quantum spin states. One of the researchers emphasized that the ability to create quantum spin qubits without the use of external magnetic fields opens up new opportunities for spintronics and topological physics.
The quantum spin Hall effect is a phenomenon where electrons in a conductor experience different potentials (Hall voltage) on opposite edges when exposed to a magnetic field, perpendicular to the current. This discovery opens up new prospects for spintronic devices in the future.