2017年11月6日 · We introduce ultrafast low-energy electron diffraction (ULEED) in backscattering for the study of structural dynamics at surfaces. Using a tip-based source of ultrashort electron pulses, we...

Since time-resolved LEED combines both high temporal and k-space resolution together with a method exclusively sensitive to the sample surface, it represents a versatile contribution to the toolbox of ultrafast surface science, which can be employed to study a multitude of sample system, such as surface reconstructions, order-disorder phenomena ...

2021年6月3日 · We investigate the optically driven phase transition between two charge-density wave (CDW) states at the surface of tantalum disulfide (1 T -TaS 2). Specifically, we employ a recently improved ultrafast low-energy electron diffraction setup to study the transition from the nearly commensurate to the incommensurate (IC) CDW state.

2019年10月8日 · The LEED intensity analysis reveals that the well-accepted model of star-of-David-shaped clusters of Ta atoms for the bulk structure also holds for the outermost two trilayers.

Single-layer TaS2 is epitaxially grown on Au(111) substrates. The resulting two-dimensional crystals adopt the 1H polymorph. The electronic structure is determined by angle-resolved photoemission spectroscopy and found to be in excellent agreement with …

2024年10月10日 · High-quality 1T-TaS 2 crystals are investigated by angle-resolved photoelectron spectroscopy, Raman spectroscopy, and low-energy electron diffraction. The Ferro-Rotational Order (FRO) of the charge density wave switches configuration at the transition between the commensurate and the nearly commensurate phase.

2020年6月22日 · Here, we employ ultrafast low-energy electron diffraction (ULEED), a recently developed surface-sensitive structural probe, 35,37–39 to give a comprehensive account of the non-equilibrium structural dynamics of the incommensurate (IC) charge-density wave phases at the surface of 1 T - TaS 2 ⁠.

1999年6月1日 · We present Fermi surface (FS) mapping measurements obtained by photoemission for the quasi-commensurate charge density wave (CDW) phase of layered 1 T -TaS 2. The topology of the FS is rather dominated by the undistorted (1×1) symmetry than by the CDW-induced (13 × 13) phase. CDW effects can be seen in terms of nesting properties of the FS.

1992年5月15日 · LEED photographs and angular resolved UPS spectra are presented to show the large differences between the commensurate and the incommensurate directions in (SnS) 1.16 TaS 2. Core level photoemission spectra indicate that there is no charge transfer from one layer to the other.

2024年12月18日 · 通过对温度变化、脉冲电压持续时间以及近红外光照对相变影响进行全面分析，揭示了多步电致相变中电流驱动和热效应驱动相变的共同作用机制，即随着电流增加，CDW相变机制从电流驱动逐渐转变为热驱动的过程。 该研究结果为统一解释 1T-TaS₂ 中电驱动电荷密度波相变机制的长期争议提供了新见解，更为基于光热耦合实现红外探测提供了崭新思路。 图1 1T-TaS2纳米片多步相变的阈值驱动行为....