15:45 〜 16:00
▲ [14p-C302-4] Plasmon-assisted Phase Transition of VO2
キーワード：phase transition, local heating, hot electron injection
We report on the observation of plasmon-assisted phase transition of vanadium dioxide embedding Au nanorod arrays. The temperature of its insulator-to-metal phase transition was manipulated by localized surface plasmons excited on the Au nanorods. At the same sample location, the phase transition temperature was apparently decreased with light polarization that excites plasmons of Au nanorods, while the temperature returned back to its original degree with the other polarization that does not excite plasmons. The phase transition temperature depends on the area density of nanorods, and the differential phase transition temperature of 3.3 ºC was observed for a nanorod area density of 8.0%. We attribute this plasmon-assisted phase transition to both local heating and the direct injection of hot electrons. This result demonstrates a new and reversible method of controlling intrinsic material properties through plasmon resonance, and could lead to novel optical switch devices compatible with complex signals.