Quantum Droplet

Quasichemistry is a branch of chemistry that studies a special type of particles called quasiparticles.

These are different from normal particles because they cannot exist individually, but only inside of solids. They act as if they were floating freely in space, with weak interactions with other particles.

For example, it is believed an electron, although a fundamental particle (the simplest substance which doesn’t have any substructure), is made of 3 quasiparticles, a holon, a spinon and an orbiton. Each of these quasiparticles has a different characteristic that codes for the electron. The holon carries the electron’s charge, the spinon its spin and the orbiton its location in the orbit.


Named dropleton because it’s like a liquid drop

However, they are not real particles, just a mathematical tool used to simplify the way electrons and nuclei move in a specific way.

There have been many quasiparticles discovered, and they are used to explore the quantum world in more depth. So every time a new quasiparticle is discovered it’s a celebration that we are closer to understanding physics at it’s smallest level.

Recently, a new quasiparticle was created, the “dropleton” (named because it’s a quantum droplet).

The way it is created is when a short laser pulse was directed at a semiconductor made of gallium arsenide. The energy given to the material causes electrons to move, creating excitons (pairs of holes in a material because of the absence of an electron). Once there are many excitons, they start joining to electrons, and moving around the solid.

But what’s interesting is the way they travel. Normal quasiparticles move like normal particles, but the dropletons flowed, rather than moved. In fact, they behaved like a group of particles in a liquid. It’s the first quasiparticles to act in a liquid fashion.

They are also special because of their longevity. They last for 25 picoseconds, which although is extremely short period of time for us humans it is quite a long time in the quantum world. This and their size (200 nanometres) allows scientists to test them and discover more about them. Not only that, but they also form stable structures. The smallest dropleton is 4 electron-hole pairs; the biggest is 14.