Nonclassicality of quantum states: a hierarchy of observable conditions.
A necessary and sufficient hierarchy of conditions is derived that is completely equivalent to the failure of the Glauber-Sudarshan P function to be a probability density. The conditions are formulated in terms of experimentally accessible characteristic functions of quadratures.
Richter
Th
T
Arbeitsgruppe Quantenoptik, Fachbereich Physik, Universität Rostock, D-18051 Rostock, Germany.
Vogel
W
W