The field of quantum information transmission is a hot field, as discussed earlier this month when we mentioned the potential progress toward quantum computers. One issue related to such quantum technologies is the transmission of quantum information, especially over long distances. Such transmission currently takes place on the Earth with new quantum encryption processes, which use the enigmatic nature of quantum physics to keep information secure from outside observers who would seek to access the information. At present, though, such transmission has been limited to only about 100 km before precision issues make the data unreadable.

A new international project has successfully demonstrated that it should be possible to transmit such information through the satellite system, as well. Their work involved firing light toward a satellite and identifying individual photons upon their return to the Earth, extending the range to 1,500 km! The transmission and reception of individual photons is crucial for quantum encryption, and the team's work proves that this can be accomplished with existing technology.

In addition to applications with quantum encryption, there are also applications toward pure research in quantum physics using such a system, which could in turn lead to a greater understanding of the limitations and possibilities of quantum physics.

Sources and Related Articles:

• New Journal of Physics - Experimental verification of the feasibility of a quantum channel between space and Earth (both abstract and full text available)
• ScienceDaily.com - Quantum Channel Between Earth And Space? Firing Photons Makes Advance In Space Communication
• Institute of Physics - Firing photons makes advance in space communication
• PhysicsWorld.com - Single photons make the trek from space
• Quantum Physics Overview
• Quantum Logic Gates Discovered?
• What is a Quantum Computer?