  Quantum conductors attached to metallic reservoirs have been demonstrated to
overcome the thermodynamic uncertainty relation (TUR), a trade-off relation
between the amount of dissipation and the absence of charge and heat current
fluctuations. Here, we report large TUR violations when superconducting
reservoirs replace metallic ones. The coexistence of different transport
processes, namely (multiple) Andreev reflection, where electrons and their
retro-reflected holes create Cooper pairs, in addition to the normal
quasiparticle transport is identified as the source for such TUR breakdowns.
The large TUR violation is a remarkable advantage for building low dissipative
and highly stable quantum thermal machines.
