A Superatomic Material Sets Speed Record

Energy and information don’t flow so well in semiconductors because the electrons and phonons in the lattice keep bumping into each other. This slows things down and causes some energy loss, which is a problem for all semiconductor gadgets.

However, now, a group of chemists at Columbia University has made quite an efficient semiconductor called Re6Se8Cl2. It’s not like regular semiconductors, and it’s special because it’s made of superatoms. They made it in their lab, reported the Tech Explorist.

In Re6Se8Cl2, something cool happens with excitons. They interact with phonons by scattering and sticking together to make new things called acoustic exciton-polarons. While we find polarons in many materials, the ones in Re6Se8Cl2 are special.

They can move really fast without getting slowed down. One day, these speedy polarons might help us make faster and better technology, mentioned the Tech Explorist.

The scientists saw that in Re6Se8Cl2, the acoustic exciton-polarons traveled twice as fast as electrons do in silicon. They could go across a lot of material in less than a tiny fraction of a second. The team thinks that these exciton-polarons can cover more than twenty-five micrometers in one go because they last for about eleven nanoseconds.

New Research | A team @ChemColumbia led by Jack Tulyag @eikonaal, a PhD student working with chemistry professor Milan Delor, describes the fastest and most efficient semiconductor yet: a superatomic material called Re6Se8Cl2. https://t.co/nG3xmpdUR0 pic.twitter.com/w8MIecEAFt

— Columbia Quantum Initiative (@ColumbiaQuantum) October 26, 2023

Moreover, in theoretical devices, the speed of operations could reach femtoseconds, which is six orders of magnitude faster than the nanoseconds used in today’s Gigahertz electronics. The reason for this incredible speed is that these special quasiparticles are guided by light instead of electricity, and this happens at room temperature.

‘Re6Se8Cl2 is the best semiconductor’

When it comes to carrying energy, Re6Se8Cl2 stands out as the best semiconductor.

Moreover, Re6Se8Cl2 was first brought into the lab by a Ph.D. student named Jack Tulyag. He wasn’t trying to find a better semiconductor, but rather, he wanted to test the lab’s microscopes using a material that wasn’t expected to conduct much.

Milan Delor, a chemistry professor, remarked, “It was the opposite of what we expected. Instead of the slow movement we expected, we saw the fastest thing we’ve ever seen.”

This surprising behavior got the scientists curious, and they wanted to figure out why Re6Se8Cl2 acted this way. They therefore created an advanced microscope with very precise abilities to watch polarons as they formed and moved through the material.

Petra Shih, who’s working towards a Ph.D. in theoretical chemistry at Timothy Berkelbach’s lab, also came up with a quantum mechanical model to explain what they saw.

Contrary to what most people might think, these new quasiparticles achieve their high speed by taking a steady pace, according to the Tech Explorist.