Two photon interference and its application in quantum metrology

KNOLL, LAURA T.; LAROTONDA, MIGUEL A.

Florianopolis

Workshop; Q-Turn: changing paradigms in quantum science; 2018

Universidade Federal de Santa Catarina, Florianópolis, Brazil.

A practical application of quantum mechanics is the measurement of magnitudes with greater sensitivity than that achievable in the same experiment performed in a classical framework. The statistical error in any estimate can be reduced by repeating the measurement and averaging the results. The central limit theorem states that the standard deviation decreases inversely proportional to the square root of the number of measurements N. This defines a lower limit in the classically accessible accuracy. However, quantum metrology allows to reach statistical accuracies higher than purely classical approaches, making use of quantum phenomena such as entanglement. We present the work in progress of an interferometer that combines two unique photons to generate an entangled N00N state, coded in polarization. This type of quantum state allows to increase the precision in the phase estimation inside the interferometer achieving an improvement with respect to the classic case, which scales as 1/N.