  A time crystal is an exotic phase of matter where time-translational symmetry
is broken; this phase differs from the spatial symmetry breaking induced in
crystals in space. Lots of experiments report the transition from a thermal
equilibrium phase to time crystal phase. However, there is no experimental
method to probe the bifurcation effect of distinct time crystals in quantum
many-body systems. Here, in a driven and dissipative many-body Rydberg atom
system, we observe multiple continuous dissipative time crystals and emergence
of more complex temporal symmetries beyond the single time crystal phase.
Bifurcation of time crystals in strongly interacting Rydberg atoms is observed;
the process manifests as a transition from a time crystal state of long
temporal order to one of short temporal order, or vice versa. By manipulating
the driving field parameters, we observe the time crystal's bistability and a
hysteresis loop. These investigations indicate new possibilities for control
and manipulation of the temporal symmetries of non-equilibrium systems.
