Amplifying Single Photons Without Noise
For many people amplifying a signal is just what happens when you turn a knob or press a button to up the volume of something. For scientists though the process can be much more complicated because amplification often introduces noise that degrades the signal they are trying to use. Researchers at Griffith University, the University of Queensland, and the University of Science and Technology of China though have developed a way to amplify the information of a single photon, without adding any noise. In fact, it can even reduce noise!
Noiseless amplifiers have been made before, but not for single photons, where quantum mechanics can get involved. In fact this new method uses quantum teleportation to operate by teleporting the signal of a noisy photon to a new, 'clean' one produced in the device. You could picture this as the old Pony Express where the rider (the signal) moves from the spent horse (the noisy photon) to a fresh one (the 'clean' photon). If that new horse is also fresher than the old one was at the beginning, the rider will get a smoother, less noisy, ride.
This discovery should have a great impact on quantum computing and communication by increasing the distance a signal may be sent. Traditional amplification would destroy the fragile state of the quantum signal making this or a similar quantum amplification method a necessity.