Formation and Control of Two-Dimension Electron Gas at the STO/LAO Interface: A Numerical Study

• Main Authors: Hsin-PanHuang, 黃心盼
• Other Authors: Yan-Ten Lu
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/04837709706679034551

碩士 === 國立成功大學 === 物理學系碩博士班 === 101 === Recent reports about the existence of two-dimension electron gas (2DEG) at the interface between STO/LAO had attracted many experimental and theoretic interests. In this thesis, we first numerically demonstrated the formation of 2DEG. A charge transfer from the impurities in LAO to STO builds the fundamental electric field at the interface for the setup of 2DEG. A most recent report showed that the concentration of 2DEG in STO/LAO/PZT hetero-structure could be enhanced or suppressed by the direction of polarization in PZT cap layer. To explain this experimental observation, we first built a model for obtaining leaking field from the PZT bound charge due to interface roughness. Then, the leaking field changed the resultant potential profile near the interface, and polarized the impurities in the STO layer. The non-uniform polarization yields an extra bound charge distribution, which produces a bump potential profile in STO layer and therefore changes the concentration of 2DEG.