  The superposition of atomic vibrations and flexoelectronic effect gives rise
to a cross correlation between free charge carriers and temporal magnetic
moment of phonons in conducting heterostructures under an applied strain
gradient. The resulting dynamical coupling is expected to give rise to
quasiparticle excitations called as magnetoelectronic electromagnon that
carries electronic charge and temporal magnetic moment. Here, we report
experimental evidence of magnetoelectronic electromagnon in the freestanding
degenerately doped p-Si based heterostructure thin film samples. These
quasiparticle excitations give rise to long-distance (>100um) spin transport;
demonstrated using spatially modulated transverse magneto-thermoelectric and
non-local resistance measurements. The magnetoelectronic electromagnons are
non-reciprocal and give rise to large magnetochiral anisotropy (0.352 A-1T-1)
that diminishes at lower temperatures. The superposition of non-reciprocal
magnetoelectronic electromagnons gives rise to longitudinal and transverse
modulations in charge carrier density, spin density and magnetic moment;
demonstrated using the Hall effect and edge dependent magnetoresistance
measurements, which can also be called as inhomogeneous magnetoelectronic
multiferroic effect. These quasiparticle excitations are analogues to photons
where time dependent polarization and temporal magnetic moment replaces
electric and magnetic field, respectively and most likely topological because
it manifests topological Nernst effect. Hence, the magnetoelectronic
electromagnon can potentially give rise to quantum interference and
entanglement effects in conducting solid state system at room temperature in
addition to efficient spin transport.
