We introduce a method to witness the quantumness of a system. The method relies on the fact that the anticommutator of two classical states is always positive. By contrast, we show that there is always a nonpositive anticommutator due to any two quantum states. We notice that interference depends on the trace of the anticommutator of two states, and it is therefore operationally more suitable to detect quantumness by looking at anticommutators of states rather than their commutators.
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - 2013 May 23|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics