| Records |
| Author |
Tang, C.S.; Zeng, S.; Wu, J.; Chen, S.; Naradipa, M.A.; Song, D.; Milošević, M.V.; Yang, P.; Diao, C.; Zhou, J.; Pennycook, S.J.; Breese, M.B.H.; Cai, C.; Venkatesan, T.; Ariando, A.; Yang, M.; Wee, A.T.S.; Yin, X. |
| Title |
Detection of two-dimensional small polarons at oxide interfaces by optical spectroscopy |
Type |
A1 Journal article |
Year  |
2023 |
Publication |
Applied physics reviews |
Abbreviated Journal |
|
| Volume |
10 |
Issue |
3 |
Pages |
031406-31409 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Two-dimensional (2D) perovskite oxide interfaces are ideal systems to uncover diverse emergent properties, such as the arising polaronic properties from short-range charge-lattice interactions. Thus, a technique to detect this quasiparticle phenomenon at the buried interface is highly coveted. Here, we report the observation of 2D small-polarons at the LaAlO3/SrTiO3 conducting interface using high-resolution spectroscopic ellipsometry. First-principles investigations show that interfacial electron-lattice coupling mediated by the longitudinal phonon mode facilitates the formation of these polarons. This study resolves the long-standing question by attributing the formation of interfacial 2D small polarons to the significant mismatch between experimentally measured interfacial carrier density and theoretical values. Our study sheds light on the complexity of broken periodic lattice-induced quasi-particle effects and its relationship with exotic phenomena at complex oxide interfaces. Meanwhile, this work establishes spectroscopic ellipsometry as a useful technique to detect and locate optical evidence of polaronic states and other emerging quantum properties at the buried interface. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
001038283300001 |
Publication Date |
2023-09-06 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1931-9401 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
15 |
Times cited |
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Open Access |
OpenAccess |
| Notes |
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Approved |
Most recent IF: 15; 2023 IF: 13.667 |
| Call Number |
UA @ admin @ c:irua:198433 |
Serial |
8847 |
| Permanent link to this record |
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| Author |
Ning, S.; Xu, W.; Ma, Y.; Loh, L.; Pennycook, T.J.; Zhou, W.; Zhang, F.; Bosman, M.; Pennycook, S.J.; He, Q.; Loh, N.D. |
| Title |
Accurate and Robust Calibration of the Uniform Affine Transformation Between Scan-Camera Coordinates for Atom-Resolved In-Focus 4D-STEM Datasets |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Microscopy and microanalysis |
Abbreviated Journal |
Microsc Microanal |
| Volume |
|
Issue |
|
Pages |
1-11 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Accurate geometrical calibration between the scan coordinates and the camera coordinates is critical in four-dimensional scanning transmission electron microscopy (4D-STEM) for both quantitative imaging and ptychographic reconstructions. For atomic-resolved, in-focus 4D-STEM datasets, we propose a hybrid method incorporating two sub-routines, namely a J-matrix method and a Fourier method, which can calibrate the uniform affine transformation between the scan-camera coordinates using raw data, without a priori knowledge about the crystal structure of the specimen. The hybrid method is found robust against scan distortions and residual probe aberrations. It is also effective even when defects are present in the specimen, or the specimen becomes relatively thick. We will demonstrate that a successful geometrical calibration with the hybrid method will lead to a more reliable recovery of both the specimen and the electron probe in a ptychographic reconstruction. We will also show that, although the elimination of local scan position errors still requires an iterative approach, the rate of convergence can be improved, and the residual errors can be further reduced if the hybrid method can be firstly applied for initial calibration. The code is made available as a simple-to-use tool to correct affine transformations of the scan-camera coordinates in 4D-STEM experiments. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000767045700001 |
Publication Date |
2022-03-09 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1431-9276 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.8 |
Times cited |
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Open Access |
OpenAccess |
| Notes |
N. D. Loh kindly acknowledges support from NUS Early Career Research Award (R-154-000-B35-133), MOE’s AcRF Tier 1 grant nr. R-284-000-172-114 and NRF CRP grant number NRF-CRP16-2015-05. Q. He would also like to acknowledge the support of the National Research Foundation (NRF) Singapore, under its NRF Fellowship (NRF-NRFF11-2019-0002). W. Zhou acknowledges the support from Beijing Outstanding Young Scientist Program (BJJWZYJH01201914430039). F. Zhang acknowledges the support of the National Natural Science Foundation of China (11775105, 12074167). T. J. Pennycook acknowledges funding under the European Union’s Horizon 2020 research and innovation programme from the European Research Council (ERC) Grant agreement No. 802123-HDEM. |
Approved |
Most recent IF: 2.8 |
| Call Number |
EMAT @ emat @c:irua:186958 |
Serial |
6957 |
| Permanent link to this record |
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| Author |
Wu, Y.; Chen, G.; Yu, J.; Wang, D.; Ma, C.; Li, C.; Pennycook, S.J.; Yan, Y.; Wei, S.-H. |
| Title |
Hole-induced spontaneous mutual annihilation of dislocation pairs |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
The journal of physical chemistry letters |
Abbreviated Journal |
J Phys Chem Lett |
| Volume |
10 |
Issue |
23 |
Pages |
7421-7425 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Dislocations are always observed during crystal growth, and it is usually desirable to reduce the dislocation density in high-quality crystals. Here, the annihilation process of the 30 degrees Shockley partial dislocation pairs in CdTe is studied by first-principles calculations. We found that the dislocations can glide relatively easily due to the weak local bonding. Our systematic study of the slipping mechanism of the dislocations suggests that the energy barrier for the annihilation process is low. Band structure calculations reveal that the band bending caused by the charge transfer between the two dislocation cores depends on the core-core distance. A simple linear model is proposed to describe the mechanism of formation of the dislocation pair. More importantly, we demonstrate that hole injection can affect the core structure, increase the mobility, and eventually trigger a spontaneous mutual annihilation, which could be employed as a possible facile way to reduce the dislocation density. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000501622700017 |
Publication Date |
2019-11-17 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1948-7185 |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
9.353 |
Times cited |
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Open Access |
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| Notes |
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Approved |
Most recent IF: 9.353 |
| Call Number |
UA @ admin @ c:irua:165068 |
Serial |
6302 |
| Permanent link to this record |
