Academic Journal
Measurement of the dynamic charge response of materials using low-energy, momentum-resolved electron energy-loss spectroscopy (M-EELS)
| العنوان: | Measurement of the dynamic charge response of materials using low-energy, momentum-resolved electron energy-loss spectroscopy (M-EELS) |
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| المؤلفون: | Sean Vig, Anshul Kogar, Matteo Mitrano, Ali A. Husain, Vivek Mishra, Melinda S. Rak, Luc Venema, Peter D. Johnson, Genda D. Gu, Eduardo Fradkin, Michael R. Norman, Peter Abbamonte |
| المصدر: | SciPost Physics, Vol 3, Iss 4, p 026 (2017) |
| بيانات النشر: | SciPost |
| سنة النشر: | 2017 |
| المجموعة: | Directory of Open Access Journals: DOAJ Articles |
| مصطلحات موضوعية: | Physics, QC1-999 |
| الوصف: | One of the most fundamental properties of an interacting electron system is its frequency- and wave-vector-dependent density response function, $\chi({\bf q},\omega)$. The imaginary part, $\chi''({\bf q},\omega)$, defines the fundamental bosonic charge excitations of the system, exhibiting peaks wherever collective modes are present. $\chi$ quantifies the electronic compressibility of a material, its response to external fields, its ability to screen charge, and its tendency to form charge density waves. Unfortunately, there has never been a fully momentum-resolved means to measure $\chi({\bf q},\omega)$ at the meV energy scale relevant to modern electronic materials. Here, we demonstrate a way to measure $\chi$ with quantitative momentum resolution by applying alignment techniques from x-ray and neutron scattering to surface high-resolution electron energy-loss spectroscopy (HR-EELS). This approach, which we refer to here as ``M-EELS" allows direct measurement of $\chi''({\bf q},\omega)$ with meV resolution while controlling the momentum with an accuracy better than a percent of a typical Brillouin zone. We apply this technique to finite-{\bf q} excitations in the optimally-doped high temperature superconductor, Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (Bi2212), which exhibits several phonons potentially relevant to dispersion anomalies observed in ARPES and STM experiments. Our study defines a path to studying the long-sought collective charge modes in quantum materials at the meV scale and with full momentum control. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| تدمد: | 2542-4653 |
| Relation: | https://scipost.org/SciPostPhys.3.4.026; https://doaj.org/toc/2542-4653; https://doaj.org/article/4fac85ff20454469a79d4c03b7d45141 |
| DOI: | 10.21468/SciPostPhys.3.4.026 |
| الاتاحة: | https://doi.org/10.21468/SciPostPhys.3.4.026 https://doaj.org/article/4fac85ff20454469a79d4c03b7d45141 |
| رقم الانضمام: | edsbas.5E5C3037 |
| قاعدة البيانات: | BASE |
Full Text Finder | تدمد: | 25424653 |
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| DOI: | 10.21468/SciPostPhys.3.4.026 |