3 ms·

Film 'built atom-by-atom' moves electrons 7x faster than semiconductors

2 points by westurner 2y ago

westurner 2y ago
> The [crystalline ternary tetradymite] film — measuring just 100 nanometers wide, or about one-thousandth of the thickness of a human hair — was created through a process called molecular beam epitaxy, which involves precisely controlling beams of molecules to build a material atom-by-atom. This process allows materials to be constructed with minimal flaws or defects, enabling greater electron mobility, a measure of how easily electrons move through a material under an electric field. > When the scientists applied an electric current to the film, they recorded electrons moving at record-breaking speeds of 10,000 centimeters squared per volt-second (cm^2/V-s). By comparison, electrons typically move at about 1,400 cm^2/V-s in standard silicon semiconductors, and considerably slower in traditional copper wiring. MBE: Molecular-Beam Epitaxy: https://en.wikipedia.org/wiki/Molecular-beam_epitaxy https://en.wikipedia.org/wiki/Molecular-beam_epitaxy
westurner 2y ago
"Quantum microscopy study makes electrons visible in slow motion" https://phys.org/news/2024-07-quantum-microscopy-electrons-visible-motion.html https://phys.org/news/2024-07-quantum-microscopy-electrons-v... .. https://news.ycombinator.com/item?id=40981039 https://news.ycombinator.com/item?id=40981039 : > If you change a few atoms at the atomic level, the macroscopic properties remain unchanged. For example, metals modified in this way are still electrically conductive, whereas insulators are not. > However, the situation is different in more advanced materials, which can only be produced in the laboratory—minimal changes at the atomic level cause new macroscopic behavior. For example, some of these materials suddenly change from insulators to superconductors, i.e., they conduct electricity without heat loss. > These changes [to superconductivity, for example] can happen extremely quickly, within picoseconds, as they influence the movement of electrons through the material directly at the atomic scale. A picosecond is extremely short, just a trillionth of a second. It is in the same proportion to the blink of an eye as the blink of an eye is to a period of more than 3,000 years. > [...] The researchers were able to optimize their microscope in such a way that it repeats the experiment 41 million times per second and thus achieves a particularly high signal quality.

2 points by westurner 2y ago

> The [crystalline ternary tetradymite] film — measuring just 100 nanometers wide, or about one-thousandth of the thickness of a human hair — was created through a process called molecular beam epitaxy, which involves precisely controlling beams of molecules to build a material atom-by-atom. This process allows materials to be constructed with minimal flaws or defects, enabling greater electron mobility, a measure of how easily electrons move through a material under an electric field. > When the scientists applied an electric current to the film, they recorded electrons moving at record-breaking speeds of 10,000 centimeters squared per volt-second (cm^2/V-s). By comparison, electrons typically move at about 1,400 cm^2/V-s in standard silicon semiconductors, and considerably slower in traditional copper wiring. MBE: Molecular-Beam Epitaxy: https://en.wikipedia.org/wiki/Molecular-beam_epitaxy https://en.wikipedia.org/wiki/Molecular-beam_epitaxy

westurner 2y ago

"Quantum microscopy study makes electrons visible in slow motion" https://phys.org/news/2024-07-quantum-microscopy-electrons-visible-motion.html https://phys.org/news/2024-07-quantum-microscopy-electrons-v... .. https://news.ycombinator.com/item?id=40981039 https://news.ycombinator.com/item?id=40981039 : > If you change a few atoms at the atomic level, the macroscopic properties remain unchanged. For example, metals modified in this way are still electrically conductive, whereas insulators are not. > However, the situation is different in more advanced materials, which can only be produced in the laboratory—minimal changes at the atomic level cause new macroscopic behavior. For example, some of these materials suddenly change from insulators to superconductors, i.e., they conduct electricity without heat loss. > These changes [to superconductivity, for example] can happen extremely quickly, within picoseconds, as they influence the movement of electrons through the material directly at the atomic scale. A picosecond is extremely short, just a trillionth of a second. It is in the same proportion to the blink of an eye as the blink of an eye is to a period of more than 3,000 years. > [...] The researchers were able to optimize their microscope in such a way that it repeats the experiment 41 million times per second and thus achieves a particularly high signal quality.