Darmstadt 2008 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

Q: Fachverband Quantenoptik und Photonik

Q 61: Quanteninformation (Photonen und nichtklassisches Licht II)

Q 61.5: Talk

Friday, March 14, 2008, 15:00–15:15, 1A

Is the role of beam-splitters in quantum optics any different from that in classical optics? — •Daniela Denot, Lev Plimak, and Wolfgang P. Schleich — Institute of Quantum Physics, Ulm University, 89069 Ulm, Germany

A statement is often made that the role of beam-splitters in quantum optics is fundamentally different from that in classical optics [1]. This statement is based on the paper by Mandel et al [2] showing that the action of a beam-splitter on a single-photon state is turning it into an entangled state of two modes. The question we ask if there exists an experimental proof of this statement. We show that the answer is negative for all photodetection measurements with two beams involving local oscillators. To prove this we devise a Gedanken-experiment where the joint photocurrent statistics of the two detectors is fully imitated in a measurement where the incident beam is detected directly. This statement is easily proven for arbitrary classical states of the incident beam while its validity for quantum states follows from the optical equivalence theorem by Sudarshan [3].
G. S. Agarwal, a talk given at the Institute of Quantum Physics, Ulm, Sept. 2007, unpublished.
C. K. Hong, Z. Y. Ou, and L. Mandel, Phys. Rev. Lett., 59(18), 2044, 1987.
E. C. G. Sudarshan. Phys. Rev. Lett., 10(7), 277, 1963.