  Twisted bilayer graphene near the magic angle exhibits remarkably rich
electron correlation physics, displaying insulating, magnetic, and
superconducting phases. Here, using measurements of the local electronic
compressibility, we reveal that these phases originate from a high-energy state
with an unusual sequence of band populations. As carriers are added to the
system, rather than filling all the four spin and valley flavors equally, we
find that the population occurs through a sequence of sharp phase transitions,
which appear as strong asymmetric jumps of the electronic compressibility near
integer fillings of the moire lattice. At each transition, a single spin/valley
flavor takes all the carriers from its partially filled peers, "resetting" them
back to the vicinity of the charge neutrality point. As a result, the
Dirac-like character observed near the charge neutrality reappears after each
integer filling. Measurement of the in-plane magnetic field dependence of the
chemical potential near filling factor one reveals a large spontaneous
magnetization, further substantiating this picture of a cascade of symmetry
breakings. The sequence of phase transitions and Dirac revivals is observed at
temperatures well above the onset of the superconducting and correlated
insulating states. This indicates that the state we reveal here, with its
strongly broken electronic flavor symmetry and revived Dirac-like electronic
character, is a key player in the physics of magic angle graphene, forming the
parent state out of which the more fragile superconducting and correlated
insulating ground states emerge.
