Quantum degenerate gas in optical lattice

" At ambient temperature, atoms in gases fly very fast with the velocity of a few hundred m/s so that trapping and looking closely at them are very difficult. With the advance of laser techniques, it has become possible to slow (cool) atoms down to a few cm/s and trap them. When atoms are cooled down to extremely low temperature (e.g. below a certain critical temperature ~ nano Kelvin range), they start behaving in a totally different and unique manner due to quantum mechanical statistics. Such system is called ‘quantum degenerate gas’ system. Quantum degenerate gas system shows various interesting quantum phenomena such as phase coherence, phase transition, and etc. Phase coherence property is one of the key properties making the ultracold gas system more ‘quantum mechanical’

Optical lattice is formed by a standing wave of a laser beam, which provides a periodic potential energy to atoms. An optical lattice is fully controllable and it offers tunability and dynamical control to quantum gas system. Combination of quantum degenerate gas and optical lattice - ultracold atoms loaded in optical lattices - provide experimental tools to realize matter-wave interferometers as well as to model many condensed matter systems, especially Hubbard model.

In this talk, I am going to talk about the experimental procedure to realize quantum degenerate gas - how we laser-cool atoms, trap them, and achieve quantum degenerate gases - and the basic physics of ultracold atoms in optical lattices. Some unique phenomena of quantum degenerate gas will be briefly introduced. The current status of experimental setup which is being built at KRISS is covered. In the end, our future plan, the application of quantum degenerate gas loaded in optical lattice to matter-wave interferometer will be discussed. "