  Recently, a novel probe to study symmetry breaking, known as entanglement
asymmetry, has emerged and has been utilized to explore how symmetry is
dynamically restored following quantum quenches. Interestingly, it has been
shown that, in certain scenarios, greater initial symmetry breaking leads to
faster restoration, akin to a quantum Mpemba effect. This study focuses on
investigating the effect of mixed initial states and non-unitary dynamics on
symmetry restoration. The mixedness of a state can arise from different
sources. We consider dephasing or dissipative processes affecting initial pure
states or unitary dynamics of initially thermal states. In the former case, the
stationary state after the quench is independent of the initial configuration,
resembling the phenomenology of the classical Mpemba effect. Investigating the
XY spin chain model, through a combination of analytical calculations and
numerical simulations, we identify the conditions for the occurrence of the
quantum Mpemba effect. It turns out that this phenomenon still occurs in the
presence of dissipation or at finite temperature, even though it will be
eventually suppressed as the state becomes more mixed.
