A scheme for measuring the purity of a quantum system with a finite number of levels is presented. The method makes use of two √swap gates and hinges only on measurements performed on a reference system, prepared in a certain pure state and coupled with the target system. Neither tomographic methods, with the complete reconstruction of the state, nor interferometric setups are needed.
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - 2012 Apr 16|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics