拓撲物理
We focus on the research of topological insulator (TI), topological semimetal, axion insulator, topological superconductor, etc., such as strong/weak TI, magnetic Dirac/Weyl semimetal, magnetic TI, unconventional TI, topological superconductivity on surface states, etc. In our previous studies, we have discovered the first hourglass fermion, Fermi arc of triple point fermion, Magnetic Weyl fermion by spin fluctuation, non-trivial magnetic Dirac fermion. We also aim to search for new kinds of quasi-fermions in crystals.
超導體
We study the electronic structure of new kinds of superconductors (SC) especially magnetic SC and coexistence of topology and superconductivity. With ARPES we can get the band structure, Fermi surface, SC gap and its symmetry, etc. ARPES provides an direct deep insight into the micro mechanism of superconductivity and plays an important role in the research of high temperature SC.
相關效應
Searching for new quantum phenomena induced by electron-boson coupling in condensed matter using ARPES will extend our understanding about the solids, which will also improve the development of device with new materials. For example, the correlation between electrons or electrons and bosons, and the (quantized) excitations of certain type of collective motion can lead to the emergence of various macroscopic quantum phenomena such as SC, charge/spin density wave, polarons, excitons, trions, etc. Exploring the rich quantum phenomena induced by electron-boson coupling in condensed matter has been a dynamic research front in the last decade and is still expected to make further progress.
Featured Research
Mobile excitons discovered in quasi-one-dimensional metal TaSe3
Charge neutrality and an expected itinerant nature makes excitons potential transmitters of information. Mobile excitons in metals have been elusive, as screening usually suppresses their formation. Very recently, using angle-resolved photoemission spectroscopy, we detect dispersing excitons for the first time in quasi-one-dimensional metallic trichalcogenide TaSe3.
Media Publicity
CityU Reports: 首次在金属中发现快速移动的激子，造就未来更高速数码通讯
未配對奇異外爾點的首次觀察
迄今為止，所有通過實驗確定的外爾半金屬 (WSM) 都具有在動量空間中成對出現的外爾點。現在，我們的研究表明，WSM 鉑鎵 PtGa 具有一個奇異的、不成對的 Weyl 點，被封閉的 Weyl 節點壁 (WNW) 包圍。這是第一次通過實驗觀察到未配對的電子 WP，也是第一次在結晶固體中通過實驗報導電子拓撲 WNW/表面。
Nature Communications第12卷，文章編號：3994（2021）
自旋漲落引起的磁性外爾費米子的首次觀察
首次觀察到拓撲三相點半金屬的表面費米弧
三點或三分量費米子是一種新的非常規費米子 在狄拉克費米子和外爾費米子的簡併之間。其拓撲非平凡性首先由表面費米弧觀測證明。
媒體宣傳
沙漏費米子的發現！
在非對稱對稱性的保護下，拓撲絕緣體的表面狀態可以形成一種特殊的結構，如沙漏，而不是普通的狄拉克錐。我們的 ARPES 實驗首先證明了這一點： 科學。高級3、e1602415 (2017) 。
媒體宣傳
揭示鐵基超導體 Ba2Ti2Fe2As4O 中相關誘導的自摻雜效應。
摻雜效應在高溫SC超導性的形成中起著重要作用。在這項工作中，我們首次證明，當我們交替地將兩種非 SC 母體化合物堆疊在一起時，它們之間的電荷轉移會驅動系統進入超導狀態。