optics logo

Ömer Bayraktar
KTH Stockholm, Sweden

Gerd Leuchs (MPL)
Ömer Bayraktar
KTH Stockholm, Sweden
N-photon, two-mode quantum state tomography

Quantum physics dictates the fundamental impossibility of determining
the polarization-state of a single photon [1]. However, applying a
series of measurements in different bases on identical copies of the
state, i.e., performing quantum state tomography, the quantum state may
be estimated [2]. Within this project the possibility of estimating the
quantum state of N photons distributed in two polarization modes in a
setup without movable components is investigated and a
proof-of-principle for the case N = 2 is demonstrated.
Therefore, a source for photon pairs is setup and characterized in
various experiments, e.g., two-photon interference and violation of the
CHSH version of Bell’s inequality. Afterwards, existing methods of
two-qubit quantum state tomography are employed. Finally, these methods
are combined with the equations for N-photon, two-mode tomography in
order to demonstrate the new tomography scheme. This method is expected
to reduce the complexity of future quantum state detection systems.

[1] A. Peres, Quantum Theory: Concepts and Methods, Springer
Netherlands, 2002.
[2] J.B. Altepeter, et al., Adv. At. Mol. Opt. Phys. 52, 105–159 (2005)
Time and Place
January 7th at 15:00
Large seminar room (429/435)