  Tailored magnetic multilayers (MMLs) provide skyrmions with enhanced thermal
stability, leading to the possibility of skyrmion-based devices for room
temperature applications. At the same time, the search for additional stable
topological spin textures has been under intense research focus. Besides their
fundamental importance, such textures may expand the information encoding
capability of spintronic devices. However, fractional spin texture states
within MMLs in the vertical dimension have yet to be investigated. In this
work, we demonstrate numerically fractional skyrmion tubes (FSTs) in a tailored
MML system. We subsequently propose to encode sequences of information signals
with fractional skyrmion tubes (FSTs) as information bits in a tailored MML
device. Micromagnetic simulations and theoretical calculations are used to
verify the feasibility of hosting distinct FST states within a single device,
and their thermal stability is investigated. A multilayer multiplexing device
is proposed, where multiple sequences of the information signals can be encoded
and transmitted based on the nucleation and propagation of packets of FSTs.
Finally, pipelined information transmission and automatic demultiplexing is
demonstrated by exploiting the skyrmion Hall effect and introducing
voltage-controlled synchronizers and width-based track selectors. The findings
indicate that FSTs can be potential candidates as information carriers for
future spintronic applications.
