The information entropy of quantummechanical states
Abstract
It is well known that a Shannonbased definition of information entropy leads in the classical case to the Boltzmann entropy. It is tempting to regard the von Neumann entropy as the corresponding quantummechanical definition. But the latter is problematic from the quantum information point of view. Consequently, we introduce a new definition of entropy that reflects the inherent uncertainty of quantummechanical states. We derive for it an explicit expression, and discuss some of its general properties. We distinguish between the minimum uncertainty entropy of pure states, and the excess statistical entropy of mixtures.
 Publication:

EPL (Europhysics Letters)
 Pub Date:
 September 2004
 DOI:
 10.1209/epl/i2004101101
 arXiv:
 arXiv:quantph/0401021
 Bibcode:
 2004EL.....67..700S
 Keywords:

 Quantum Physics;
 Mathematical Physics
 EPrint:
 7 pages, 1 figure