Topological magnetization jumps in a confined chiral soliton lattice

We demonstrate that a finite-size chiral soliton lattice formed in a chiral helimagnet with fixed boundary conditions exhibits magnetization jumps in a response to the magnetic field applied perpendicular to the chiral axis. The imposed boundary conditions lead to confinement of topological charges and quantized spatial periods of the soliton lattice. Building an envelope of the ground-state energies belonging to different topological sectors, we find the magnetization jumps related with the level crossing. After numerically establishing the quantization condition, we also develop a field-theoretical model to support the numerical results.