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Gap inhomogeneity in Bi2Sr2CaCu2O8+δ revealed by laser micro-ARPES
https://repo.qst.go.jp/records/82420
https://repo.qst.go.jp/records/82420a610bc8a-b4b0-4558-b8b5-dd95b469a3a4
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2021-03-23 | |||||
| タイトル | ||||||
| タイトル | Gap inhomogeneity in Bi2Sr2CaCu2O8+δ revealed by laser micro-ARPES | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Sugiyama, T.
× Sugiyama, T.× Hideaki, Iwasawa× Oda, H.× Ozawa, S.× Kono, T.× Kimura, A.× Ishida, S.× Yoshida, Y.× Eisaki, H.× Hideaki, Iwasawa |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Since the discovery of the high-Tc superconductivity in copper oxides (cuprates), the cuprate superconductors have been extensively investigated experimentally and theoretically. Nevertheless, the mechanism of the high-Tc superconductivity has not been clarified yet. The order parameter, the superconducting gap, of the high-Tc superconductivity has been particularly investigated. Angle-resolved photoemission spectroscopy is known as the powerful tool to prove the superconducting gap in a momentumresolved manner, which fingerprinted the d-wave gap symmetry. On the other hand, scanning tunneling spectroscopy/microscopy allows to observe the superconducting gap, and the nano-scale inhomogeneity was in the real-space was reported in Bi2Sr2CaCu2O8+δ (Bi2212) [1]. However, such real-space inhomogeneity has not been fully considered in the conventional ARPES studies due to its poor spatial resolution (~ mm scale). To overcome this problem and study the evolution of the superconducting gap in the real- and momentum-space, we have performed high-resolution micro-ARPES experiments on underdoped Bi2212 (Tc = 65 K) using a micro-focused laser (hν = 6 eV) at the Hiroshima Synchrotron Radiation Center, Hiroshima University. Figure 1(a) shows the ARPES image of the underdoped Bi2212 taken along the nodal direction (see inset) in the superconducting state (T= 20 K). We have then measured such a clear band dispersion from the nodal to the off-nodal direction (see inset) and evaluated the momentum dependence of the gap. In addition, we have also examined the real-space dependence of the superconducting gap by performing the same measurement while slightly changing the measurement position on the sample surface. Figure 1(b) compares the momentum dependence on the gap magnitude taken from the two different measurement positions (A and B). We found that the gap magnitude and its momentum dependence are clearly different in spite of the small difference (less than 0.1 mm) on the measurement position. To examine the momentum dependence quantitatively, we fit the experimental results by the gap function [2]. The fitting analysis showed that the antinodal gap for position A is larger than one for position B, while the nodal gap for position A is smaller than one for position B. In other words, our results suggest the inverse correlation between the superconducting gap and the pseudogap. In this talk, we will discuss the observed real-space and momentum-space dependence on the superconducting gap and the pseudogap in detail. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | The 25th Hiroshima International Symposium on Synchrotron Radiation | |||||
| 発表年月日 | ||||||
| 日付 | 2021-03-04 | |||||
| 日付タイプ | Issued | |||||
