Chinese scientists develop controllable chiral graphene rolls for spintronics

TIANJIN -- A research team from Tianjin University has introduced a new technique, the wax-aided immersion method, which could produce controllable chiral graphene rolls.

This advancement provides a novel approach to chirality modulation in two-dimensional materials and their potential applications in spintronics, laying a solid foundation for future developments in quantum computing and spintronic devices, according to the team.

The study was recently published in Nature Materials.

Chirality refers to the property of objects whose mirror images cannot be perfectly superimposed, much like the relationship between our left and right hands. In materials science, the development of chiral materials is crucial for advancing frontier technologies such as optical devices, spintronics, and quantum computing.

Graphene, a classic two-dimensional material known for its high electrical conductivity, excellent mechanical strength, and chemical stability, has long been a focal point of material science research. However, graphene itself is achiral.

In recent years, scientists have attempted to introduce chirality into graphene and other two-dimensional materials by rolling them up, and exploring their potential new characteristics and applications. Currently, few two-dimensional materials possess chirality-based spintronics functionality, and there is a lack of universal methods for fabrication.

The team's research allows for the controlled rolling of graphene at specific angles to create chiral graphene rolls.

Experimental results demonstrated that the left-handed and right-handed graphene rolls exhibited significant optical activity and remarkable spin-selectivity effects. Through precise control of the chiral angle, the team also achieved control on chiral-induced spin-selectivity, which holds unique application potential for spintronics.

Furthermore, the researchers observed that electrons primarily moved along one side of the graphene roll, leading to preferential spin polarization. This chiral-induced spin-selectivity effect opens new possibilities for developing efficient spin filters and spintronic devices.

"This research not only offers a universal method for chirality control in non-chiral two-dimensional materials, but also paves new avenues for exploring quantum behavior and developing room-temperature spintronic technologies," said Lei Shengbin, a team member.

In the future, this technique is expected to enable unique functionalities that surpass traditional carbon materials in fields such as spintronics, quantum computing, optical devices, and material science, injecting new vitality into the development of spintronics and quantum technologies, Lei added.