[11a-Z06-1~12] 6.6 Probe Microscopy

▲ [11a-Z06-11] Nanoscale phase transition of Ge₂Sb₂Te₅ induced by locally enhanced laser fields at a tunnel junction

〇(M2)DANGIL KIM¹, Kanta Asakawa^1,2, Shotaro Yaguchi¹, Mikito Tsujii¹, Keisuke Kaneshima¹, Katsumasa Yoshioka¹, Yusuke Arashida³, Shoji Yoshida³, Hidemi Shigekawa³, Masashi Kuwahara⁴, Ikufumi Katayama¹, Jun Takeda¹ (1.Yokohama Natl. Univ., 2.Tokyo Univ. of Agriculture and Technology, 3.Tsukuba Univ., 4.AIST)

Keywords:phase change material, scanning tunneling microscopy

Ge₂Sb₂Te₅ (GST), a representative phase change material (PCM) has been extensively investigated as a promising candidate for next-generation data storage and processing devices, because of its outstanding processing performance and durability. It has been reported that the irradiation of the femtosecond laser pulses on GST induces the ultrafast amorphization, where the flipping of Ge atom takes place from the octahedral to the tetrahedral symmetry site. By utilizing a scanning tunneling microscope (STM) coupled with femtosecond laser pulses, we demonstrate that nanometer-scale amorphous marks can be induced by locally enhanced laser fields at a tunnel junction.