Regional Jet 700 ER/LR (CRJ700)
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Inflight Event / Encounter Wake Vortex Encounter
Flight Crew Regained Aircraft Control
Environment - Non Weather Related; Procedure
Significant wake turbulence associated with takeoff behind A321. Departing Runway 25R at PHX; [we were] lined up and cleared for takeoff behind a departing A321 as it rotated downfield.  Our takeoff sequence started normally with flex numbers and a standard rotation at Vr.  Between 100-200 feet AGL; we experienced an abrupt roll to the left of approximately 20-30 degrees.  Aircraft control was immediately regained as we cleared the wake of the preceding aircraft.  This is the second encounter I've had departing behind a presumably 'heavy' A321 and encountering such significant wake turbulence; however this is the first time it has occurred so low the ground.  Tower cleared our takeoff just as the [preceding] aircraft wheels left the pavement in which we then began our takeoff roll. It may be considered advisable to further follow similar events with regional aircraft taking off behind A321.  An immediate departure behind this aircraft type should possibly be delayed to avoid wake turbulence at low altitudes.
Reporter stated this was a very unsettling event given the low altitude at which it occurred.
CRJ-700 Captain reported encountering wake turbulence shortly after takeoff from PHX in trail of an A321.