Sequence of unsharp measurements enabling a real-time visualization of a quantum oscillation
Abstract
The normalized state \|ψ(t)>=c1(t)\|1>+c2(t)\|2> of a single two-level system performs oscillations under the influence of a resonant driving field. It is assumed that only one realization of this process is available. We show that it is possible to approximately visualize in real time the evolution of the system as far as it is given by \|c2(t)\|2. For this purpose we use a sequence of particular unsharp measurements separated in time. They are specified within the theory of generalized measurements in which observables are represented by positive operator-valued measures. A realization of the unsharp measurements may be obtained by coupling the two-level system to a meter and performing the usual projection measurements on the meter only.
- Publication:
-
Physical Review A
- Pub Date:
- May 2001
- DOI:
- 10.1103/PhysRevA.63.052102
- arXiv:
- arXiv:quant-ph/0008026
- Bibcode:
- 2001PhRvA..63e2102A
- Keywords:
-
- 03.65.Ta;
- 42.50.-p;
- Foundations of quantum mechanics;
- measurement theory;
- Quantum optics;
- Quantum Physics
- E-Print:
- 17 pages, 3 figures, accepted for publication in Phys. Rev. A. Some typographical corrections are made and a short treatmeant of the fidelity of our measurements (N-series) is added