Thermal rectification in Y-junction carbon nanotube bundle

Active control of heat flow is one of the important concepts in phononic devices, among which thermal diode is a fundamental building block. The long-standing bottleneck is the relevant experiments lagging far behind theoretical results. In this paper, we experimentally demonstrated considerable thermal rectification in the Y-junction carbon nanotube (CNT) bundle with suspended thermal bridge method. The thermal rectification ratio is up to ∼8.3% ± 0.5% with a relatively low temperature difference (ΔT = 4K). Molecular dynamics simulation results show that asymmetric phonon transmission in different (forward and backward) directions is responsible for the thermal rectification observed in the asymmetric CNT structure.