• 3 Omega
• Nanowires
• Thermal Conductivity
• Thermoelectricity
• Twinning Superlattice

We present experimental evidence of a significant reduction in thermal conductivity in InAsSb polytypic heterostructures known as Twinning Superlattice Nanowires, together with unaltered electrical transport properties at room temperature with respect to homogeneous InAsSb nanowires. These results were obtained on suspended devices with the all-electrical 3 Omega method for measuring the thermal conductivity of the samples. The drastic reduction in thermal transport without impacting electrical conductivity highlights the potential for twinning superlattice nanowires as a novel platform for thermoelectric applications.