DOI: 10.1073/pnas.1916792117
论文题名: Atomic fluctuations in electronic materials revealed by dephasing
作者: Palato S. ; Seiler H. ; Nijjar P. ; Prezhdo O. ; Kambhampati P.
刊名: Proceedings of the National Academy of Sciences of the United States of America
ISSN: 0027-8424
出版年: 2020
卷: 117, 期: 22 语种: 英语
英文关键词: Coherence mapping
; Electronic coherence
; Quantum coherence
; Two-dimensional electronic spectroscopy
; Ultrafast spectroscopy
Scopus关键词: cadmium selenide
; quantum dot
; Article
; controlled study
; correlation analysis
; electricity
; phonon
; priority journal
; quantum mechanics
; sensitivity analysis
; spectroscopy
; vibration
英文摘要: The microscopic origin and timescale of the fluctuations of the energies of electronic states has a significant impact on the properties of interest of electronic materials, with implication in fields ranging from photovoltaic devices to quantum information processing. Spectroscopic investigations of coherent dynamics provide a direct measurement of electronic fluctuations. Modern multidimensional spectroscopy techniques allow the mapping of coherent processes along multiple time or frequency axes and thus allow unprecedented discrimination between different sources of electronic dephasing. Exploiting modern abilities in coherence mapping in both amplitude and phase, we unravel dissipative processes of electronic coherences in the model system of CdSe quantum dots (QDs). The method allows the assignment of the nature of the observed coherence as vibrational or electronic. The expected coherence maps are obtained for the coherent longitudinal optical (LO) phonon, which serves as an internal standard and confirms the sensitivity of the technique. Fast dephasing is observed between the first two exciton states, despite their shared electron state and common environment. This result is contrary to predictions of the standard effective mass model for these materials, in which the exciton levels are strongly correlated through a common size dependence. In contrast, the experiment is in agreement with ab initio molecular dynamics of a single QD. Electronic dephasing in these materials is thus dominated by the realistic electronic structure arising from fluctuations at the atomic level rather than static size distribution. The analysis of electronic dephasing thereby uniquely enables the study of electronic fluctuations in complex materials. © 2020 National Academy of Sciences. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/163462
Appears in Collections: 气候变化与战略
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作者单位: Palato, S., Department of Chemistry, McGill University, Montréal, QC H3A 0B8, Canada; Seiler, H., Department of Chemistry, McGill University, Montréal, QC H3A 0B8, Canada; Nijjar, P., Department of Chemistry, University of Southern California, Los Angeles, CA 90089, United States; Prezhdo, O., Department of Chemistry, University of Southern California, Los Angeles, CA 90089, United States; Kambhampati, P., Department of Chemistry, McGill University, Montréal, QC H3A 0B8, Canada
Recommended Citation:
Palato S.,Seiler H.,Nijjar P.,et al. Atomic fluctuations in electronic materials revealed by dephasing[J]. Proceedings of the National Academy of Sciences of the United States of America,2020-01-01,117(22)