The phase of matter where the particles do not move is called a Bose-Einstein condensate (BEC). In this state, a large number of bosons (particles that have integer spin) are cooled to very low temperatures and brought into a state of coherence, meaning that they behave as a single quantum mechanical entity. In a BEC, the particles are all in the same quantum state and have the same energy. Therefore, they do not move relative to each other, but they exhibit collective behavior. BECs are usually created in dilute atomic gases and have remarkable properties such as superconductivity and superfluidity.