Bose liquid, a quantum liquid in which the elementary excitations (quasiparticles) have zero or integer spin and obey Bose—Einstein statistics. The Bose liquids include, for example, liquid 4He, which at low temperature can pass into the state of superfluidity, which has specific quantum properties (see Liquid helium). Another example — the collection of Cooper pairs of electrons, whose formation leads to superconductivity.