PRECISION MEASUREMENT TO STUDY STRONGLY CORRELATED SYSTEMS-FROM A SINGLE ION TO PHONONS IN AN ION CHAIN

Abstract

Emulation of isolated strongly correlated quantum many-body systems has been a subject of intense experimental and theoretical research in recent years. Trapped ions are well-controlled quantum systems and the ideal choice for studying the strongly correlated systems to unfold the correlated physics. In this thesis, both theoretical and experimental studies on a strongly correlated system have been performed. In the theoretical section, the main part is devoted to studying the phonon dynamics in trapped ion system where the dynamics are governed by strongly correlated Bose-Hubbard Hamiltonian. Trapped ion system allows us to tune the onsite phonon-phonon interaction from positive to negative which leads to several interesting phenomena which have been investigated in the theoretical section. One of this studies shows that the ramp dynamics can be used for both generating multiparticle entanglement as well as motional ground state cooling of a chain of trapped ions. The experimental work performed within this thesis is centered around probing the strongly correlated many electron systems in a heavy atom, barium. A new method of measuring the branching fraction and hence electronic wavefunction of barium atom is proposed and implemented in a linear Paul trap experiment. This measurement provides a benchmark to test the many-body theories to uncertainties below 1% level. As the experimental setup has been developed during this thesis a detail of the setup and its systematic relevant to precision measurement are discussed in details here. In addition, the thesis includes observation of new reference lines from tellurium spectroscopy which are relevant for barium and other atomic transitions close to 455 nm.