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| Main Authors: | , , , , , |
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| Format: | Preprint |
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2014
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/1403.1543 |
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| _version_ | 1866916493205176320 |
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| author | Girlando, Alberto Masino, Matteo Schlueter, John A. Drichko, Natalia Kaiser, Stefan Dressel, Martin |
| author_facet | Girlando, Alberto Masino, Matteo Schlueter, John A. Drichko, Natalia Kaiser, Stefan Dressel, Martin |
| contents | We report comprehensive Raman and infrared investigations of charge-order (CO) fluctuations in the organic metal $β^{\prime\prime}$-(BEDT-TTF)$_2$SF$_5$CHFSO$_3$ and superconductor $β^{\prime\prime}$-(BEDT-TTF)$_2$SF$_5$CH$_2$CF$_2$SO$_3$. The charge-sensitive vibrational bands have been analyzed through an extension of the well-known Kubo model for the spectral signatures of an equilibrium between two states. At room temperature, both salts exhibit charge fluctuations between two differently charged molecular states with an exchange frequency of about $6\times10^{11} {\rm s}^{-1}$. The exchange rate of the metallic salt remains roughly constant down to 10 K, while in the superconductor the exchange velocity starts to decrease below 200 K, and a "frozen" charge-ordered state emerges, and coexists with the charge-order fluctuation state down to the superconducting temperature. These findings are confronted with other existing spectroscopic experiments, and a tentative phase diagram is proposed for the $β^{\prime\prime}$ BEDT-TTF quarter-filled salts. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_1403_1543 |
| institution | arXiv |
| publishDate | 2014 |
| record_format | arxiv |
| spellingShingle | Charge-order fluctuations and superconductivity in two-dimensional organic metals Girlando, Alberto Masino, Matteo Schlueter, John A. Drichko, Natalia Kaiser, Stefan Dressel, Martin Superconductivity We report comprehensive Raman and infrared investigations of charge-order (CO) fluctuations in the organic metal $β^{\prime\prime}$-(BEDT-TTF)$_2$SF$_5$CHFSO$_3$ and superconductor $β^{\prime\prime}$-(BEDT-TTF)$_2$SF$_5$CH$_2$CF$_2$SO$_3$. The charge-sensitive vibrational bands have been analyzed through an extension of the well-known Kubo model for the spectral signatures of an equilibrium between two states. At room temperature, both salts exhibit charge fluctuations between two differently charged molecular states with an exchange frequency of about $6\times10^{11} {\rm s}^{-1}$. The exchange rate of the metallic salt remains roughly constant down to 10 K, while in the superconductor the exchange velocity starts to decrease below 200 K, and a "frozen" charge-ordered state emerges, and coexists with the charge-order fluctuation state down to the superconducting temperature. These findings are confronted with other existing spectroscopic experiments, and a tentative phase diagram is proposed for the $β^{\prime\prime}$ BEDT-TTF quarter-filled salts. |
| title | Charge-order fluctuations and superconductivity in two-dimensional organic metals |
| topic | Superconductivity |
| url | https://arxiv.org/abs/1403.1543 |