Researchers develop maser as tiny as rice grain using quantum dots

In a rare invention, the researchers at Princeton University have successfully developed a tiny microwave laser or “maser”, which is as small as a rice grain, using quantum dots.

The maser is equipped with quantum dots that are artificial atoms. In greater depth, quantum dots are the small particles of light-emitting nanocrystals that have the ability to absorb light from one wavelength and then convert it to extremely saturated light at certain wavelengths.

The so-called “maser” emits light at much longer wavelengths in comparison to the traditional forms of lasers.

According to the researchers behind the study, the newly developed device could also help in making greater advancements in quantum computing.

The maser works very efficiently with the help of single electrons travelling through the quantum dots just like an effective power source.

Some of the other advantages of quantum dots include improvement in the look of LCD screens on smartphones, tablets and television sets.

The researchers explain when the quantum dots are excited due to a current flow, they start emitting powerful light. This makes them a greater medium for building lasers.

Physics professor Jason Petta led the Princeton team for the study to build a small device like a transistor, known as a double-dot micromaser. The maser possesses four quantum dots in two pairs that are placed inside as well as toward the closing stage of a narrow cavity.

The quantum dots placed in each pair are divided by nearly 500 nanometers. It’s just like an average strand of human hair which is nearly 100,000 nanometers wide.

The researchers further explain there are tiny wires between each pair that are nearly 150 nanometers apart. The wires are arranged in such a way that they appeared like crossing the path like a fence from one dot to another. The complete setup functions just like a transistor, with one dot works as the current source and another one as the drain, and the wires like gate electrodes.

The study was reported online in the journal Science on January 15.