Quantumness Measure from Phase Space Distributions

Ole Steuernagel^1*, Ray-Kuang Lee¹

¹Photonics, NTHU, Hsinchu, Taiwan

* Presenter:Ole Steuernagel, email:librarole@gmail.com

A recent approach [Bohmann and Agudelo, Phys. Rev. Lett. 124, 133601 (2020)] allows for
the discriminating and noise-tolerant detection of non-classical behaviour of quantum states. But
it does not provide a sensitive measure for the quantumness of states; to date no such measure is
known. We amend Bohmann and Agudelo’s approach such that it inherits the multiple strengths of
the original proposal whilst providing a quantumness measure, Ξ. Ξ is discriminating, exquisitely
sensitive and grows monotonically with an increase in the system’s non-classical excitations.
We compare this measure to other measures showing that Ξ has good features not shared by other measures.

Keywords: quantumness, phase space , Wigner distribution