Quantum Information and Communication

The use of quantum systems as carriers of information has the potential to revolutionize communications. All communications technologies now in commercial use are based on "classical" technology - ordinary bits and bytes in systems like optical fibers. Over the next few decades this will change as new technologies based on the principles of quantum mechanics are developed. The rules of quantum mechanics are radically different from the rules that govern not just our ordinary everyday life, but also all the communications technologies now in existence.

Changing the rules at such a fundamental level completely changes what can be done. Moving to quantum mechanical systems enables new technologies and capabilities beyond what is possible for classical communication systems. Of particular importance for communication are techniques such as:

Quantum cryptography:
- Unbreakable methods for secret communication;
Distributed quantum computation:
- Methods for solving distributed problems using less communication than is required classically;
Quantum error-correction:
- Reduces the effects of noise on quantum systems, and thus enables the development of other quantum technologies such as quantum computers;
Quantum teleportation:
- For transporting the state of quantum mechanical systems from one location to another.

Key Research Challenges

Quantum information is extremely new and is currently undergoing very rapid development. Many questions remain unanswered, including fundamental questions like "how much information can be transmitted through a quantum channel". At a more practical level, although many surprising and important applications of quantum information are already known, it seems likely that we have as yet barely scratched the surface of the potential applications.

Key research challenges include the following:

Develop a theory of quantum information, including capacity formulas telling us how much information can be transmitted through a quantum channel;
Develop the theory of quantum error-correcting codes, determining the fundamental limits and capabilities of quantum error-correction;
Develop new applications of quantum communication to application areas such as cryptography, distributed computation, and communication;
Develop technologies capable of fully realizing the promise of quantum communication.

More Information

Quantum information science initiative at the University of Queensland;
Qubit.org, with many tutorials and other resources;
Scientific American article, a popular science article by Prof. Michael Nielsen from University of Queensland.