Nambu-Goldstone mode in trapped Bose-Einstein condensation

摘要

In 1995, Bose-Einstein condensation (BEC) of neutral atoms were realized owing to laser cooling techniques. Since a gas of atoms is dilute and the atomic interactions are weak, these systems give us the test fields for theories which are intended to describe the quantum many-body problem, i.e. quantum statistical mechanics, quantum field theory (QFT) and thermal field theory (TFT).