The symmetry caused by light in small crystals allow researchers to create materials with designed properties

Imagine building the Lego tower with completely alignment blocks. Each corn block is in a small crystal, known as the quantum point. Just like the collision of the tower can change the blocks and change its structure, external forces can transform the atoms at a quantitative point, break the symmetry and affect their properties.

Scientists have learned that they can break the symmetry – or restore symmetry – in quantum points to create new materials with unique properties. In a recent study, researchers at the US Department of Energy National Laboratory discovered how to use light to change the arrangement of atoms in these small structures.

The quantum points made of semiconductor materials, such as lead sulfide, are known for their unique visual and electronic properties due to their small size, which gives them the ability to revolutionize fields such as electronics and medical imaging. By harnessing the ability to control symmetry in these quantum points, scientists can customize materials to obtain specific properties related to light and electricity. This research opens new possibilities for designing materials that can perform the tasks that have already been impossible, providing a way to innovative technologies.

Usually, lead sulfide is expected to form a cubic crystal structure, characterized by high symmetry similar to that table salt. In this structure, lead and sulfur atoms must arrange themselves in a very arranged poetry, such as many red and blue LEGOs.

However, the previous data suggested that lead atoms were not specifically as it was expected to be. Instead, they were a little outside the center, which led to a brown with less consistency.

“When the symmetry changes, it can change the properties of a substance, almost similar to a completely new material,” Ergon physics explained Richard Shaler. “There is a lot of attention to the scientific community to find ways to create cases that cannot be produced under normal circumstances.”

The team used advanced X -ray laser and X -ray techniques to study how lead sulfide scores changing when exposed to light. In the Slac’s National Accelerator Laboratory, they used a tool called Megaelectronvolt Ultrafast Electron electron olives (MEV-UPP) to monitor the behavior of these quantum points in incredibly short time frame frameworks, up to second trillion.

Meanwhile, at the APS source, a DOE of Science user in Argonne, they conducted the experiences of outstanding overall X-rays using Leamline 11-D-D to study temporary structural changes in the time range up to one billion seconds. These X -ray measurements have benefited from the last APS upgrade, which provides high -energy X -rays of 500 times more brighter than before.

In addition, at the Nano Materials Center, another facility for DOE of Science users in Argonne, the team rapidly performed – less than trillion from visual absorption measurements to understand how electronic processes change when symmetry changes. These modern facilities in Argonne and SLAC have played a decisive role in helping researchers learn more about the control of symmetry and visual characteristics of quantum points on very rapid time domains.

Using these techniques, the researchers noted that when the quantum points were subjected to short motivations of light, the correspondence of the crystal structure changed from a turbulent condition to one more organized.

“When quantum points absorb a slight pulse, exciting electrons convert the material to a more consistent arrangement, as lead atoms are due to a axis mode,” said Burak Guzilork, a physicist in APS.

The return of symmetry directly affected the electronic properties of quantum points. The team noted a decrease in the power gap power, which is the difference in the energy that electrons need to jump from one state to another inside the semiconductor material. This change can affect the success of crystals in electricity and response to external forces, such as electric fields.

Moreover, researchers also discussed how quantum points and surface chemistry affect temporary changes in symmetry. By controlling these factors, they can control symmetry transformations and adjust visual and electronic properties of quantum points.

“We often assume that the crystal structure does not really change, but these new experiences show that the structure is not always fixed when absorbing light,” Shaler said.

The results of this study are important for nanotechnology and technology. To be able to change the correspondence of quantum points using only light pulses that allow scientists to create specific properties and functions. Just as LEGO bricks can be converted into endless structures, researchers learn how to “build” quantum points with the characteristics they want, which paves the way for new technological progress.

The results of this research were published in Advanced materials.