Quantum technologies

Our group’s 2D Discrete Quantum Simulator (DQSIM) experiment is dedicated to the idea of a discrete time quantum walk. A quantum walk is the quantum mechanical analogue of a classical random walk. Discrete refers here to the timing in which evolution operators are applied to two quantum systems, a walker and a coin. It not only exhibits different statistics than the classical counterpart but may be employed in a multitude of ways. For example the experimental simulation of a perfect conductor in which Bloch oscillations are performed or the simulation of topological systems that are otherwise inaccessible in solid state physical scales.

The first chapter reviews the DQSIM setup and necessary concepts to assess the place the content of the thesis is going to take within the experimental effort of our group. Then this thesis deals with two additions to the DQSIM experiment. The first part concerns a specifically designed photodiode amplifier circuit to improve the intensity stabilization of the lattice beams. Improving it would ensure that the coherence time of the atoms isn’t limited by intensity noise any more.

The second part introduces a scheme to realize compression of atomic ensembles trapped in our optical lattice. Furthermore it is a first step in achieving an efficient single plane selection and addressing in our experiment opening the door to many-particle quantum walks. The thesis concludes with a discussion about initial experimental attempts on compression and a summary of the results.