Introduction to Quantum Physics and Information Processing

182 Introduction to Quantum Physics and Information Processing

9.2 Quantum Dense Coding

An interesting aspect of quantum information transfer is how one can

actually transfer two classical bits of information while physically transmitting

only one qubit. This process seems to involve compressing two bits into one

qubit and is accordingly called dense coding. The key to the process is the

use of entanglement. This protocol preceded and inspired the teleportation

protocol discussed above [10]. So our friends Alice and Bob enter the picture

with their shared Bell state, which they are going to use as a resource to

communicate two bits of information b