New electric field signals strong potential for quantum computing

Researchers from City University of Hong Kong (CityUHK) have observed a new vortex electric field with the potential to enhance future electronic, magnetic and optical devices. The research, published in Science, could upgrade the operation of many devices by strengthening memory and computing speed. With further research, the discovery of the vortex electric field could even later impact the fields of quantum computing, spintronics and nanotechnology.

Professor Ly Thuc Hue from CityUHK said that generating a vortex electric field previously required expensive thin film deposition techniques and complex procedures. “However, our research has demonstrated that a simple twist in bilayer 2D materials can easily induce this vortex electric field,” Hue said.

To achieve a clean interface, researchers typically synthesised bilayers directly. However, it is challenging to maintain freedom in twisting angles, particularly for low-angle twists. Hue’s team developed the ice-assisted transfer technique, which has been crucial for achieving a clean interface between bilayers, allowing them to manipulate and create twisted bilayers freely.

Unlike previous studies that focused on twist angles smaller than three degrees, the team’s technique allowed them to create a broad spectrum of twist angles ranging from 0 to 60 degrees, by leveraging both synthesis and artificial stacking through ice-assisted transfer. The discovery of the new vortex electric field in the twisted bilayer has also created a 2D quasicrystal, potentially enhancing future electronic, magnetic and optical devices. Quasicrystals are desirable irregularly ordered structures due to their low heat and electric conductivity, making them suitable for high-strength surface coatings such as in frying pans.

According to Hue, these structures can have a range of applications as the vortex electric field generated differs depending on the angle of the twist. The quasicrystals can result in a more stable memory effect for electric devices, ultrafast mobility and speed for computing, dissipationless polarisation switching, novel polarisable optical effects and advancements in spintronics.

The researchers overcame many obstacles on their path to making the new observations; first by establishing a clean interface between bilayers. This led them to discover a new technique that uses ice as a transfer material. By synthesising and transferring 2D materials using a thin sheet of ice, the researchers achieved clean interfaces that were easy to manipulate. Compared to other techniques, this ice-assisted transfer technique is more effective and less time-consuming.

The researchers then overcame the challenge of analysing the material. The discovery was made using four-dimensional transmission electron microscopy (4D-TEM) and through collaboration with other researchers. In one of the stages of testing, the twisted bilayer 2D structure was created and the new vortex electric field was observed.

“This study had the potential to ignite a new field focused on twisting vortex fields in nanotechnology and quantum technology,” Hue said.

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