TY  - JOUR
A1  - Menzel, Ralf
A1  - Marx, Robert
A1  - Puhlmann, Dirk
A1  - Heuer, Axel
A1  - Schleich, Wolfgang
T1  - The photon
BT  - the role of its mode function in analyzing complementarity
JF  - Journal of the Optical Society of America : B, Optical physics
N2  - We investigate the role of the spatial mode function in a single-photon experiment designed to demonstrate the principle of complementarity. Our approach employs entangled photons created by spontaneous parametric downconversion from a pump mode in a TEM01 mode together with a double slit. Measuring the interference of the signal photons behind the double slit in coincidence with the entangled idler photons at different positions, we select signal photons of different mode functions. When the signal photons belong to the TEM01-like double-hump mode, we obtain almost perfect visibility of the interference fringes, and no "which slit" information is available in the idler photon detected before the slits. This result is remarkable because the entangled signal and idler photon pairs are created each time in only one of the two intensity humps. However, when we break the symmetry between the two maxima of the signal photon mode structure, the paths through the slits for these additional photons become distinguishable and the visibility vanishes. It is the mode function of the photons selected by the detection system that decides if interference or "which slit" information is accessible in the experiment.
Y1  - 2019
U6  - https://doi.org/10.1364/JOSAB.36.001668
SN  - 0740-3224
SN  - 1520-8540
VL  - 36
IS  - 6
SP  - 1668
EP  - 1675
PB  - Optical Society of America
CY  - Washington
ER  - 
TY  - JOUR
A1  - Eisenberg, Peter
A1  - Menzel, Wolfgang
T1  - Grammatik-Werkstatt : Basisartikel
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Menzel, Ralf
A1  - Puhlmann, Dirk
A1  - Heuer, Axel
A1  - Schleich, Wolfgang P.
T1  - Wave-particle dualism and complementarity unraveled by a different mode
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - The precise knowledge of one of two complementary experimental outcomes prevents us from obtaining complete information about the other one. This formulation of Niels Bohr's principle of complementarity when applied to the paradigm of wave-particle dualism-that is, to Young's double-slit experiment-implies that the information about the slit through which a quantum particle has passed erases interference. In the present paper we report a double-slit experiment using two photons created by spontaneous parametric down-conversion where we observe interference in the signal photon despite the fact that we have located it in one of the slits due to its entanglement with the idler photon. This surprising aspect of complementarity comes to light by our special choice of the TEM01 pump mode. According to quantum field theory the signal photon is then in a coherent superposition of two distinct wave vectors giving rise to interference fringes analogous to two mechanical slits.
Y1  - 2012
U6  - https://doi.org/10.1073/pnas.1201271109
SN  - 0027-8424
VL  - 109
IS  - 24
SP  - 9314
EP  - 9319
PB  - National Acad. of Sciences
CY  - Washington
ER  -