Researchers belonging to the Princeton University have made a laser which is extremely small – about the size of a single grain of rice, powering it using artificial atoms called quantum dots.
The laser, being small itself, obviously generates only a tiny amount of energy (around a billionth the amount of electricity that is required to power up and use a typical hair dryer). Using the quantum dots as a power source, the laser makes use of a single electron, and tunnels through this power source.
The researchers say that the tiny laser is a source of energy in itself (in the range of microwave frequencies), that could be a way which would be used to demonstrate how light and moving electrons interact.
The new microwave laser, dubbed maser is a significant step forward in quantum computing. These could guide the way to build a computing system from a semiconductor material quantum dots.
Through the use of nanowires whose diameter is a mere 50 nm or nanometers, the researchers have made the quantum dots with even more diminutive metal wires which controlled the limit of the amount of energy that the dots could contain.
Next, as a means of containing, two double dots were placed around 6 millimeters away from each other in a niobium cavity, which brings the temperature down of the entire apparatus to absolute zero. Scientists were able to make the quantum dots to emit microwave photos, that bounced off the mirrors which have been affixed to each end of the niobium cavity, creating the microwave light.