Professor Oh Sang-ho succeeded in verifying electron distribution through a microscope
- 성균융합원
- Hit2821
- 2018-04-02
Professor Oh Sang-ho (SKKU Energy Science dept.) succeeded in verifying electron distribution through a microscope
Successful verification of electron distribution by microscope ... "Application to Interface Electron Characterization"
△ Dimensional electromagnetic gas in which the crystal orientation is formed at an oxide interface different from the crystal orientation. When the crystal orientation of the LaAlO3 / SrTiO3 oxide controlled at the atomic unit is changed from (001) to (111), the distribution width of the two-dimensional electron gas widenes from about 1 nm to 3 nm. In order to image the change in the electron distribution due to the quantum phenomenon, a microscopic observation method which is sensitive to electrons and has excellent spatial resolution is needed.
Sungkyunkwan University Professor Oh Sang-ho and Dr. Song Kyung Materials Research Institute team have succeeded in observing two-dimensional electron gas under a microscope.
The precise control of electron quantity to form at a desired location or to move quickly is closely related to the performance of semiconductor memory devices.
Therefore, to control the elcetrons effectively, high-resolution microscopic observation methods are needed to visually verify and anlayze the theoretically predicted electron distribution.
Using inline electronic holography with high sensitivity, the research team developed a visual inspection of two-dimensional electron gas formed between two oxides (LaAlO3 / SrTiO3).
The two-dimensional electron gas refers to a conductive electron bunch formed at the interface between two materials.
Signals are weak to observe with an electron microscope. Several variable effects should also be considered.
△ A conceptual diagram of inline electron holography method applied to oxide interface where two - dimensional electron gas exists.
The team analyzed the inherent properties of the two-dimensional electron gas by accurately calibrating all the variable factors.
Based on this, it was confirmed that the distribution and the density of the two-dimensional electron gas are finely changed according to the crystal orientation (the angle and direction in which the atoms are bonded).The researchers explained that the quantum phenomenon occurs because the electron energy level changes according to the direction of observation.
Professor Oh Sang-ho said, "It is the first observation of electron distribution and density change caused by various quantum phenomena, and it can be used to analyze the surface and interfacial electron characteristics described in the physical theory."
The research was carried out by the Ministry of Science and Technology, Ministry of Information and Communication, the Korea Research Foundation, the Future Material Discovery Project, the Basic Research Project (Advanced Research), and the US Air Force Asia Office (AOARD).
The paper on the achievements was published in the March issue of Nature Nanotechnology.