  We investigate which momentum components of gluons induce color confinement
and spontaneous chiral symmetry breaking in lattice QCD. For this purpose, we
formulate a lattice framework to introduce the momentum cutoff of the gluon
field. Using this framework, we calculate the quark-antiquark potential, the
color flux tube, the chiral condensate, and the Dirac spectrum. Our results
suggest that confinement and chiral symmetry breaking are induced by somehow
different momentum components of gluons.
