Direct estimation of decoherence rates
Abstract
The decoherence rate is a nonlinear channel parameter that describes quantitatively the decay of the off-diagonal elements of a density operator in the decoherence basis. We address the question of how to experimentally access such a nonlinear parameter directly without the need for complete process tomography. In particular, we design a simple experiment working with two copies of the channel, in which the registered mean value of a two-valued measurement directly determines the value of the average decoherence rate. No prior knowledge of the decoherence basis is required.
- Publication:
-
Physical Review A
- Pub Date:
- November 2012
- DOI:
- 10.1103/PhysRevA.86.052109
- arXiv:
- arXiv:1207.3053
- Bibcode:
- 2012PhRvA..86e2109B
- Keywords:
-
- 03.65.Wj;
- 03.65.Yz;
- 03.65.Ta;
- 03.67.-a;
- State reconstruction quantum tomography;
- Decoherence;
- open systems;
- quantum statistical methods;
- Foundations of quantum mechanics;
- measurement theory;
- Quantum information;
- Quantum Physics
- E-Print:
- 7 pages, 2 figures, v2: reference added