Bachelor defense by Emilia M. K. Telléus

Titel: Excitation errors from off-resonant excitation in entanglement generation

Abstract: Entangled photons are useful for both error correcting of quantum signals travelling over long transmission distances and in quantum computing. One method of creating such photons is a protocol relying on the driving of transitions in a three-level quantum system. The possibility of a fourth level necessitates the optimisation of the length of the pulse, which is used to drive the frequencies, and this requires the calculation of the coe?cients of the system. An analytical description of this is attempted at both in a bare state basis and a dressed state basis but the results are both found not to correspond with the numerical solutions. In the case of the dressed state basis, the di?erential equations can be rewritten as an integral, but this integral cannot be solved analytically without the use of approximations that do not hold for most pulses. Further investigations has not been able to provide a satisfactory description of the system.