  Helical magnets are emerging as a novel class of materials for spintronics
and sensor applications; however, research on their charge and spin transport
properties in a thin film form is less explored. Herein, we report the
temperature and magnetic field dependent charge transport properties of a
highly crystalline MnP nanorod thin film over a wide temperature range (2-350
K). The MnP nanorod films of 100 nm thickness were grown on Si substrates at
500 oC using molecular beam epitaxy. The temperature dependent resistivity data
exhibits a metallic behavior over the entire measured temperature range.
However, large negative magnetoresistance of up to 12% is observed below 50 K
at which the system enters a stable helical (screw) magnetic state. In this
temperature regime, the MR(H,T) dependence seems to show a magnetic field
manipulated phase coexistence. The observed magnetoresistance is dominantly
governed by the intergranular spin dependent tunneling mechanism. These
findings pinpoint a correlation between the transport and magnetism in this
helimagnetic system.
