Jeong Seung Gyo, Min Taewon, Woo Sungmin, Kim Jiwoong, Zhang Yu-Qiao, Cho Seong Won, Son Jaeseok, Kim Young-Min, Han Jung Hoon, Park Sungkyun, Jeong Hu Young, Ohta Hiromichi, Lee Suyoun, Noh Tae Won, Lee Jaekwang, Choi Woo Seok
Department of Physics, Sungkyunkwan University, Suwon 16419, Korea.
Department of Physics, Pusan National University, Busan 46241, Korea.
Phys Rev Lett. 2020 Jan 17;124(2):026401. doi: 10.1103/PhysRevLett.124.026401.
Artificial crystals synthesized by atomic-scale epitaxy provide the ability to control the dimensions of the quantum phases and associated phase transitions via precise thickness modulation. In particular, the reduction in dimensionality via quantized control of atomic layers is a powerful approach to revealing hidden electronic and magnetic phases. Here, we demonstrate a dimensionality-controlled and induced metal-insulator transition (MIT) in atomically designed superlattices by synthesizing a genuine two-dimensional (2D) SrRuO_{3} crystal with highly suppressed charge transfer. The tendency to ferromagnetically align the spins in an SrRuO_{3} layer diminishes in 2D as the interlayer exchange interaction vanishes, accompanying the 2D localization of electrons. Furthermore, electronic and magnetic instabilities in the two SrRuO_{3} unit cell layers induce a thermally driven MIT along with a metamagnetic transition.
通过原子尺度外延合成的人工晶体能够通过精确的厚度调制来控制量子相的维度以及相关的相变。特别是，通过对原子层进行量子化控制来降低维度，是揭示隐藏的电子和磁相的有力方法。在此，我们通过合成具有高度抑制电荷转移的真正二维（2D）SrRuO₃晶体，在原子设计的超晶格中展示了维度可控且诱导的金属 - 绝缘体转变（MIT）。随着层间交换相互作用消失，SrRuO₃层中自旋铁磁排列的趋势在二维中减弱，同时伴随着电子的二维局域化。此外，两个SrRuO₃单胞层中的电子和磁不稳定性会引发热驱动的MIT以及变磁转变。
