Bachelor defense by Kasper H. Nielsen

Titel: Quantum Sensing under the effect of colored noise 

Abstract: "In this thesis we investigate the impact of noise on the experimental setup of Ramsey Spectroscopy.

In the first part of this thesis, we derive the standard quantum limit in a Markovian environment, where the presence of white noise dictates the precision of measurements. Our result matches previous findings, but is derived from a more general setting.

We move on to a non-Markovian environment. Here it has previously been shown that one can obtain a better precision than the standard quantum limit in terms of parameters $T$ and $L$ - being the total time of the experiment and number of atoms respectively. \par In our model we choose a spectral density function consisting of white noise with colored noise added on top - where the colored noise is represented by a Gaussian.

We find that in our model it is not possible to surpass the fundamental scaling of the white noise limit. We also find that the precision of a measurement is limited by the peak value of the spectral density function, in the case where we assume pure colored noise."