Partial quantum information

By Michal Horodecki, Jonathan Oppenheim, Andreas J. Winter. Nature, 2005

430 citations recorded by the source corpus.

Information—be it classical or quantum—is measured by the amount of communication needed to convey it. In the classical case, if the receiver has some prior information about the messages being conveyed, less communication is needed. Here we explore the concept of prior quantum information: given an unknown quantum state distributed over two systems, we determine how much quantum communication is needed to transfer the full state to one system. This communication measures the partial information one system needs, conditioned on its prior information. We find that it is given by the conditional entropy—a quantity that was known previously, but lacked an operational meaning. In the classical case, partial information must always be positive, but we find that in the quantum world this physical quantity can be negative. If the partial information is positive, its sender needs to communicate this number of quantum bits to the receiver; if it is negative, then sender and receiver instead gain the corresponding potential for future quantum communication. We introduce a protocol that we term ‘quantum state merging’ which optimally transfers partial information. We show how it enables a systematic understanding of quantum network theory, and discuss several important applications including distributed compression, noiseless coding with side information, multiple access channels and assisted entanglement distillation.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/8a716a4c1afeaa7ec49f23c90f2dc0d7311fb08b

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Artificial Intelligence

  1. Fernando G. S. L. Brandão
  2. Michal Horodecki
  3. Renato Renner
  4. Andreas J. Winter
  5. Matthias Christandl
  6. Mario Berta
  7. Patrick M. Hayden
  8. Sándor Imre

In Atomic and Molecular Physics, and Optics

  1. Fernando G. S. L. Brandão
  2. Michal Horodecki
  3. Renato Renner
  4. Andreas J. Winter
  5. Matthias Christandl
  6. Mario Berta
  7. Patrick M. Hayden
  8. Sándor Imre

Citations in the corpus