Precision-controlled ultrafast electron microscope platforms. A case study: Multiple-order coherent phonon dynamics in 1T-TaSe2 probed at 50 fs-10 fm scales

被引：0

作者：

Sun, Xiaoyi ^{[1
]}

Williams, Joseph ^{[1
]}

Sharma, Sachin ^{[1
]}

Kunjir, Shriraj ^{[2
]}

Morris, Dan ^{[2
]}

Zhao, Shen ^{[2
]}

Ruan, Chong-Yu ^{[1
]}

机构：

[1] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA

[2] Michigan State Univ, Facil Rare Isotope Beams, E Lansing, MI 48824 USA

来源：

STRUCTURAL DYNAMICS-US | 2024年 / 11卷 / 02期

基金：

美国国家科学基金会;

关键词：

CHARGE-DENSITY WAVES; STRUCTURAL DYNAMICS; PHASE; SPECTROSCOPY; FIELDS;

D O I：

10.1063/4.0000242

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We report on the first detailed beam tests attesting the fundamental principle behind the development of high-current-efficiency ultrafast electron microscope systems where a radio frequency (RF) cavity is incorporated as a condenser lens in the beam delivery system. To allow for the experiment to be carried out with a sufficient resolution to probe the performance at the emittance floor, a new cascade loop RF controller system is developed to reduce the RF noise floor. Temporal resolution at 50 fs in full-width-at-half-maximum and detection sensitivity better than 1% are demonstrated on exfoliated 1T-TaSe2 system under a moderate repetition rate. To benchmark the performance, multi-terahertz edge-mode coherent phonon excitation is employed as the standard candle. The high temporal resolution and the significant visibility to very low dynamical contrast in diffraction signals via high-precision phase-space manipulation give strong support to the working principle for the new high-brightness femtosecond electron microscope systems. (c) 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)

引用

页数：13