Ultrafast Lasers Can Condense Electrons and Holes on Semiconductors
In collaboration with theorists at the University of Marburg in Germany, physicists at the American Astrophysics Joint Research Laboratory have discovered a new class of quasiparticles that use ultrafast 1000mw laser pointer to allow multiple electrons and holes in a semiconductor to be replaced by new Way arrangement of combinations, condensed into a liquid-like "quantum droplets." Although the life span is only 25 picoseconds (1 picoseconds = trillionths of a second), the stability of quantum droplets is sufficient to study how light and matter interact with a specific form.
When electrons flow through the semiconductor, they leave a hole in the original position. Electrons can be combined with holes in pairs, known as the exciton, is a kind of quasi-particles. The newly discovered quasiparticle is a microscopic complex in which electrons and holes are arranged in an unpaired manner. The researchers call it "quantum droplets," because it has both quantum properties, such as well-ordered energy levels, but also has some liquid properties, such as can produce ripples. It is different from the liquid water we are familiar with because quantum dots are very limited in size and beyond this limit the correlation between electrons and holes disappears.
In this experiment, the research team to gallium arsenide semiconductor emitted about 100 million pulses per second ultra-fast red 500mw laser pointer. The laser pulse first generates excitons, and as the intensity of the pulse increases, more electron-hole pairs are created. But when the exciton density reaches a certain level, the original binding of electrons and holes will be dissolved. The electrons then form a circular wave around the hole, just like the arrangement of the atoms in the liquid. At the pressure of the surrounding plasma, negatively charged electrons and positively charged holes are & quot; squeezed & quot; into neutral & quot; droplets. & Quot; The researchers found that four electrons and four holes are enough to form a drop of "droplets", up to "droplets" in the number of electrons and holes can reach 14.
The researchers say that their experimental data on individual "droplet" levels are in agreement with theoretical calculations. The quantum properties of the blue laser pointer pulse can be adjusted to match the energy level to the correlation of the particles inside the droplet. "Droplets" appear to be sufficiently stable to contribute to the future systematic study of the interaction between light and matter states. Moreover, quasiparticles often possess unique properties not possessed by their constituent particles and can play a role in controlling larger systems and devices. "When it comes to practical use, nobody is going to develop a 'quantum droplet' device," says Stephen Kandiff, a physicist at the American Astrophysics Joint Research Lab. "But it does indirectly deepen our understanding of the difference between electrons in different , Including how to interact in optoelectronic devices. "
In recent years, with the improvement of experimental technology, scientists have extensively studied the extreme conditions of the nature of condensed matter, found a lot of new physical phenomena, semiconductor electron-hole droplets is a very attractive new Garden. This "quantum droplet" compared to ordinary small water droplets, can be described as a drop in the ocean. It now appears that this little thing seems to be no practical use, from the development of "quantum droplets" small device there is a certain 3000mw laser pointer distance. But not to be underestimated is that with our understanding of the interaction between optoelectronic devices continue to deepen, Bao Bu Qi day there will be a significant scientific research was born, brought us great surprises.
http://laserman123.promblogus.com/blogs/35230-Picosecond_Laser_is_the_Future_of_3C_Processing.html
https://www.scribd.com/document/330378361/Burning-Laser-Pointers-10-Watt
