Atomic Scale Epitaxy Group
- Prof. Tae Won Noh
- http://recfi.snu.ac.kr/
The Atomic-Scale Epitaxy Group, led by Prof. Tae Won Noh, is the first group to be established within the IBS Center for Correlated Electron Systems. Our research group studies the physics of strongly correlated electron systems, focusing on the state-of-the-art epitaxial synthesis of transition-metal-oxide thin films. The atomic-scale fabrication of artificial heterostructures enables us to create arrangements that do not exist in bulk materials, providing new settings for the study of emergent phenomena.
We aim to obtain a comprehensive understanding of these artificial systems with the aid of numerous spectroscopy methods; including optical, terahertz pump-probe, and angle-resolved photoemission spectroscopy, as well as utilizing scanning probe microscopy. Unraveling the underlying mechanisms of strong correlation phenomena, and their possible manipulation may pave the way toward new functional devices for future practical applications, with the possibility of overcoming the current limitations of semiconductor electronics.
We aim to obtain a comprehensive understanding of these artificial systems with the aid of numerous spectroscopy methods; including optical, terahertz pump-probe, and angle-resolved photoemission spectroscopy, as well as utilizing scanning probe microscopy. Unraveling the underlying mechanisms of strong correlation phenomena, and their possible manipulation may pave the way toward new functional devices for future practical applications, with the possibility of overcoming the current limitations of semiconductor electronics.
Main Equipment
Ultrafast spectroscopy
Ultrafast spectroscopy is a powerful tool to measure a system with intertwined degree of freedoms, by unwinding complexed responses in time domain. We utilize RegA 9040, Coherent Co., Ti:Sapphire laser as the source of pump and probe beam. We utilize optical (1.55 eV), second-harmonic generated UV (3.1 eV) and terahertz (0.2-7 THz, 9-20 THz) electromagnetic wave to probe the ultrafast photoexcited state of matters. The cryostat enables low-temperature measurement whose lower limit of temperature is 6 Kelvin.
Variable temperature spectroscopic ellipsometer
Spectroscopic ellipsometer is a powerful tool to measure the optical properties of the material simultaneously. With the cryogenic vacuum chamber, our equipment provides the temperature-dependent optical spectra of the film and crystalline.
Pulsed Laser Deposition
There has been a growing interest in transition metal oxide heterostructures and its emergent physical properties. Pulsed Laser Deposition is a versatile tool for constructing the high-quality complex oxide heterostructures. Using reflection high energy electron diffraction, we can do in-situ monitoring of the oxide film growth and realize atomically defined heterointerfaces. Laser diode substrate heating systems allow maximum sample temperature ~ 1,100 ºC and fast heating/cooling.
Atomic Force Microscopy (AFM)
In nano-scale, correlated oxides exhibit exotic phenomena which differs from the properties in bulk. We characterize the nano-scale physical properties of complex oxide heterostructures via AFM. Combined with conductive or magnetic probes, AFM can investigate emergent nano-scale functionalities such as piezo-response, conductivity, magnetism, electrostatic forces, and work functions.