Ayaka Usui, Exploration of quantum states with cold atoms

Speaker: Ayaka Usui, Quantum Systems (Busch) Unit

Title: Non-Classical Properties of Few-Particle Systems with Synthetic Spin-Orbit

Abstract: Since Bose-Einstein condensation in a cold alkali gas was first observed in 1995, systems of cold atoms have been attracting attention owing to the high tunability of parameters and the confining potential, allowing one to create isolated systems with clean environments. Particularly, the realisation of the isolated system has motivated one to investigate non- equilibrium phenomena and quantum thermodynamics. The realisation of multi-component Bose-Einstein condensates enables one to consider the pseudo-spin degree of freedom. Cold atoms are neutral in terms of charges, but recently the induction of synthetic spin-orbit coupling to two-component Bose-Einstein condensates was achieved in particular by optical manipulation using two Raman lasers. For this thesis project, I propose to investigate a system of two bosons in one dimension in the presence of spin-orbit coupling. The two bosons are described by two identical atoms with different hyperfine states, and can therefore be regarded as a two-level system with a pseudo-spin. I have investigate the ground state and the energy spectrum of the system so far. For the next project, I will engineer the system by controlling the parameters dynamically and suggest a process to create spatial superposition states as a function of the internal state of the atoms. While for very strong interactions this will lead to a NOON state, which is a useful state in quantum metrology, the achievable states for finite interaction strengths are non-trivial to predict. It is expected that this project provides a powerful and realisable platform for quantum metrology and quantum information with few-body systems and it will also give theoretical insight into the physics of quantum thermodynamics.

After the seminar (17:00-17:30), join us for discussion with free pizza and soft drinks!