Thees Maximilian, Lee Min-Han, Bouwmeester Rosa Luca, Rezende-Gonçalves Pedro H, David Emma, Zimmers Alexandre, Fortuna Franck, Frantzeskakis Emmanouil, Vargas Nicolas M, Kalcheim Yoav, Le Fèvre Patrick, Horiba Koji, Kumigashira Hiroshi, Biermann Silke, Trastoy Juan, Rozenberg Marcelo J, Schuller Ivan K, Santander-Syro Andrés F
Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France.
Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, CA 92093, USA.
Sci Adv. 2021 Nov 5;7(45):eabj1164. doi: 10.1126/sciadv.abj1164. Epub 2021 Nov 3.
In solids, strong repulsion between electrons can inhibit their movement and result in a “Mott” metal-to-insulator transition (MIT), a fundamental phenomenon whose understanding has remained a challenge for over 50 years. A key issue is how the wave-like itinerant electrons change into a localized-like state due to increased interactions. However, observing the MIT in terms of the energy- and momentum-resolved electronic structure of the system, the only direct way to probe both itinerant and localized states, has been elusive. Here we show, using angle-resolved photoemission spectroscopy (ARPES), that in VO, the temperature-induced MIT is characterized by the progressive disappearance of its itinerant conduction band, without any change in its energy-momentum dispersion, and the simultaneous shift to larger binding energies of a quasi-localized state initially located near the Fermi level.
在固体中，电子之间的强排斥作用会抑制其运动，并导致“莫特”金属-绝缘体转变（MIT），这是一种基本现象，50多年来，对其的理解一直是个挑战。一个关键问题是，由于相互作用增强，波状的巡游电子如何转变为类似局域化的状态。然而，从系统的能量和动量分辨电子结构的角度观察MIT，这是探测巡游态和局域态的唯一直接方法，却一直难以实现。在此，我们利用角分辨光电子能谱（ARPES）表明，在VO中，温度诱导的MIT的特征是其巡游导带逐渐消失，而其能量-动量色散没有任何变化，同时，一个最初位于费米能级附近的准局域态向更大结合能处发生位移。
