  Many studies have revealed that confined water chain flipping is closely
related to the spatial size and even quantum effects of the confinement
environment. Here, we show that these are not the only factors that affect the
flipping process of a confined water chain. First-principles calculations and
analyses confirm that quantum tunnelling effects from the water chain itself,
especially resonant tunnelling, enhance the hydrogen bond rotation process.
Importantly, resonant tunnelling can result in tunnelling rotation of hydrogen
bonds with a probability close to 1 with only 0.597 eV provided energy.
Compared to sequential tunnelling, resonant tunnelling dominants water chain
flipping at temperatures up to 20 K higher. Additionally, the ratio of the
resonant tunnelling probability to the thermal disturbance probability at 200 K
is at least ten times larger than that of sequential tunnelling, which further
illustrates the enhancement of hydrogen bond rotation brought about by resonant
tunnelling.
