Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 174.28; Flight Crew Total 11000; Flight Crew Type 4000
Inflight Event / Encounter Wake Vortex Encounter; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control
Environment - Non Weather Related; Procedure
I was the CA/LCA on the flight.  First leg of trip with new CA student.  I was PF in the right seat; acting as F/O.  On descent into DEN on LAWGR arrival.  Turbulence was forecast for descent to DEN below FL200.  Fasten seat belt sign was on and F/A were briefed about turbulence and completing their duties early.  We were about 1 min from making PA for the FAs to take their jump seats.  DEN Center had cleared us to descend via. Appropriate altitude set in MCP.  Aircraft on autopilot; in LNAV and VNAV Path; 280KTS. In VMC and at approximately FL260; we experienced what we determined to be a wake turbulence event.  The aircraft rolled left and then hard to the right.  Amber caution on PFD and verbal caution 'Roll Authority'.  I disengaged the autopilot; verbalized 'my aircraft' and hand flew roll recovery to stabilize the aircraft.  Whole event lasted less than 5 sec (my estimate).  With aircraft stabilized and continuing on lateral/vertical path; I re-engaged autopilot B.  Other than the hard rolls; turbulence was nothing more than light; if even that.  I asked the CA student to make PA announcement for F/A to take jump seats; which he did.  Less than 5 sec after engaging Autopilot B; we had a 2nd wake turbulence event.  Again; with hard rolls left and right; with 'Roll Authority' cautions.  I disengaged autopilot; verbalized 'my aircraft'; and hand flew the aircraft until stabilized.  Event lasted no more than 5 sec (my estimate).  CA student notified ATC of wake event.  ATC said we were following an A320.  ATC then cleared us to slow to 250kts.  With aircraft stable again; I re-engaged autopilot and then set 250kts in FMC descent page.  A normal descent and landing were then accomplished with no further issues.
B737NG Captain reported encountering wake turbulence on descent into DEN in trail of an A320.