Terahertz conductivity of localized photoinduced carriers in a Mott insulator YTiO3 at low excitation density, contrasted with the metallic nature in a band semiconductor Si
Use this link to cite this item : https://ir.lib.hiroshima-u.ac.jp/00021461
ID | 21461 |
file | |
creator |
Tsubota, M.
Iga, Fumitoshi
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NDC |
Physics
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abstract | We performed optical-pump terahertz-probe measurements of a Mott insulator YTiO3 and a band semiconductor Si using a laser diode (1.47 eV) and a femtosecond-pulse laser (1.55 eV). Both samples possess long energy-relaxation times (1.5 ms for YTiO3 and 15 mu s for Si); therefore, it is possible to extract terahertz complex conductivities of photoinduced carriers under equilibrium. We observed highly contrasting behaviour-Drude conductivity in Si and localized conductivity possibly obeying the Jonscher law in YTiO3. The carrier number at the highest carrier-concentration layer in YTiO3 is estimated to be 0.015 per Ti site. Anisotropic conductivity of YTiO3 is determined. Our study indicates that localized carriers might play an important role in the incipient formation of photoinduced metallic phases in Mott insulators. In addition, this study shows that the transfer-matrix method is effective for extracting an optical constant of a sample with a spatially inhomogeneous carrier distribution.
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journal title |
Journal of Physics-Condensed Matter
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volume | Volume 19
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issue | Issue 40
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start page | 406224
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date of issued | 2007-10
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publisher | IOP Publishing Ltd
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issn | 0953-8984
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publisher doi | |
language |
eng
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nii type |
Journal Article
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HU type |
Journal Articles
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DCMI type | text
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format | application/pdf
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text version | author
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rights | Copyright(c) 2007 IOP Publishing Ltd
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relation is version of URL | http://dx.doi.org/10.1088/0953-8984/19/40/406224
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department |
Graduate School of Advanced Sciences of Matter
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