Quantum phase investigation of a single nuclear spin in a magnetic molecule

More than a hundred years ago, physicists used thought experiments to debate the controversial point of quantum theory while undoing the experimental constraints. Since then, advances in experimental techniques offer physicists the opportunity to study systems worthy of those imagined by the founders of the quantum theory. During the presentation, we will investigate the quantum dynamic of one of these toy model systems, namely a single 3/2 nuclear spin.
We will first see how to measure a single electronic [1] and nuclear spin using a molecular magnet transistor. Then we will couple the nuclear spin to a microwave electric field [2] and measure the coherent manipulation of the 3 nuclear spin transitions, thus demonstrating a full controlled of a 4-level quantum system, a qudit [3]. With their state space of dimension d>2, Qudits open fascinating experimental prospects. In this presentation I will show implementation of protocols based on a generalization of the Ramsey interferometry to a multi-level system to measure the accumulation of geometric phases and of quantum gate phase [4].

[1] Godfrin C. et al. ACS Nano 11, 3984 (2017)
[2] Thiele S. et al. Science 344, 1135 (2014)
[3] Godfrin C. et al. Phys. Rev. Lett. 119, 187702 (2017)
[4] Godfrin C. et al. npj Quant. inf. 4, 53 (2018)