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  -