  We derive the quantization of magnetic helicity in the solid-state and
demonstrate tunable macroscopic quantum tunneling, coherence, and oscillation
for a skyrmion spin texture stabilized in frustrated magnets. We also discuss
the parameter space for the experimental realization of quantum effects.
Typically, for a skyrmion of 5 nm radius, quantum tunneling between two
macroscopic states with distinct helicities occurs with an inverse escape rate
within seconds below 100 mK, and an energy splitting in the MHz regime.
Feasibility of quantum tunneling of an ensemble of magnetic spins inspires new
platforms for quantum operations utilizing topologically protected chiral spin
configurations.
