$^{13}$C NMR Study on Zero-Gap State in the Organic Conductor $θ$-(BEDT-TTF)$_{2}$I$_{3}$ under Pressure

K. Miyagawa; M. Hirayama; M. Tamura; K. Kanoda

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arXiv · 1004.2527

$^{13}$C NMR Study on Zero-Gap State in the Organic Conductor $θ$-(BEDT-TTF)$_{2}$I$_{3}$ under Pressure

K. Miyagawa·M. Hirayama·M. Tamura·K. Kanoda

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Abstract

We present the results of our $^{13}$C NMR study of the quasi-two-dimensional organic conductor $θ$-(BEDT-TTF)$_2$I$_{3}$ under pressure, which is suggested to be a zero-gap conductor by transport measurements. We found that NMR spin shift is proportional to $T$ and that spin-lattice relaxation rate follows the power law $T^α$ ($α=3 \sim 4$), where $T$ is the temperature. This behavior is consistent with the cone-like band dispersion and provides microscopic evidence for the realization of the zero-gap state in the present material under pressure.

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K. Miyagawa, M. Hirayama, M. Tamura, K. Kanoda. 2010-04-15. $^{13}$C NMR Study on Zero-Gap State in the Organic Conductor $θ$-(BEDT-TTF)$_{2}$I$_{3}$ under Pressure. https://arxiv.org/abs/1004.2527

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