5 papers
Optimal estimates and joint measurement uncertainty relations
Michael J. W. Hall
Often, one would like to determine some observable A, but can only measure some (hopefully related) observable M. This can arise, for example, in quantum eavesdropping, or when the…
Exact uncertainty properties of bosonic fields
Michael J. W. Hall, Kailash Kumar, Marcel Reginatto
(A) The momentum density conjugate to a bosonic quantum field splits naturally into the sum of a classical component and a nonclassical component. It is shown that the field and th…
Exact uncertainty relations: technical details
Michael J. W. Hall
The Heisenberg inequality ΔX ΔP \geq \hbar/2 can be replaced by an exact equality, for suitably chosen measures of position and momentum uncertainty, which is valid for all wavefun…
Comment on "Conceptual Inadequacy of Shannon Information ..." by C. Brukner and A. Zeilinger
Michael J. W. Hall
It is pointed out that the case for Shannon entropy and von Neumann entropy, as measures of uncertainty in quantum mechanics, is not as bleak as suggested in quant-ph/0006087. The…
Volume of classical and quantum ensembles: geometric approach to entropy and information
Michael J. W. Hall
It is shown for classical and quantum ensembles that there is a unique quantity which has the properties of a "volume". This quantity is a function of the ensemble entropy, and hen…