TRIQ - Quantum Information & Relativity Theory Group

Introduction

Quantum information theory has developed dramatically in the last 20 years and has been revolutionary in the way it has changed how we think about information and computation. It is clear that within a few years communication protocols based on quantum mechanics will be common. Already experiments have been performed showing how to communicate with ”absolute” security across a distance of 144 km. Experiments have also been done on communication with satellites in space using lasers. Combining these advances would lead to secure communication with satellites.
This kind of communication puts one firmly in the realm of relativistic effects. For example, the GPS system requires that clocks are synchronized to an accuracy of 20 to 30 nanoseconds. If relativistic corrections were not made to the clock rates then they would get out of sync by almost 40 microseconds per day; a factor of 2000 away from what is needed. In the case of quantum communication there would be entirely new phenomena to deal with.
The laws of quantum information in this setting are poorly understood. In particular we do not know general principles for calculating information transmission rates or how to overcome the effects of noise in quantum communication protocols that arise in some relativistic situations. On the other hand, there are also (so far rare) examples where relativity can be used to achieve security in situations where it is provably impossible without relativity, even using quantum mechanics.
This project is set up to explore and formulate the fundamental laws of information theory and communication in a fully relativistic and quantum setting. Part of our goal is to understand the implications for cryptography and information flow. Finally, on the positive side we want to develop new communication paradigms and protocols that make use of relativistic effects.
This project is funded by the Office of Naval Research as part of a Basic Research Challenge under the Broad Agency Announcement 08-007.