7/14(목) 물리학과 문은국 교수 연구실에서 개최하는 세미나를 안내 드립니다.
- Title: Pure two-dimensional quantum electron liquid and its phase transition
- Speaker: Dr. Sunghun Kim(Institute of Natural Science, KAIST)
- Date: Jul. 14th (THU), 15:00, E6 #1501
https://us02web.zoom.us/j/87068327099?pwd=SXlyZTRkSnhEeW1GTlFjaW45SW1nUT09
회의 ID: 870 6832 7099
암호: 977538
- Abstract:
Pure electrons spread in two-dimensional (2D) space can have several different phases of gas, liquid, and even solid – so called Wigner crystal, determined by their kinetic and potential energies. In quantum regime, it is expected to have diverse intermediate phases between Fermi liquid and Wigner crystal phase rendered by the quantum fluctuation with exclusive electron-electron interactions. In this regard, there have been many efforts to realize pure quantum electron phases and unveil its intriguing physics. However, the requirements to realize such quantum electrons at solid systems set a huge hurdle that the most of the experimental investigations have been limited in the classical regime so far.
In this talk, I present the discovery of pure 2D quantum electron liquid formed on solid 2D electride at relatively high temperature of 10 K and its phase transition. Using photoemission spectroscopy and first-principles calculation, we characterized the dense surface electrons decoupled from the top-most layer that means free from other degrees of freedom. By reducing the density of 2D electron system, we observed dynamics change to that of non-Fermi liquid along with anomalous band deformation, accompanied by conserved translational symmetry and reduced rotational symmetry, that suggests a possible phase transition to the hexatic liquid crystal phase. These results can provide further opportunities to study the role of electron-electron interaction which can drive Wigner crystal and various intermediate phases in quantum regime
