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On the superconducting state of the organic conductor $(TMTSF)_2ClO_4$

J. Shinagawa·Y. Kurosaki·F. Zhang·C. Parker·S. E. Brown·D. Jerome·J. B. Christensen·K. Bechgaard
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Abstract

$(TMTSF)_2ClO_4$ is a quasi-one dimensional organic conductor and superconductor with $T_c=1.4$K, and one of at least two Bechgaard salts observed to have upper critical fields far exceeding the paramagnetic limit. Nevertheless, the $^{77}$Se NMR Knight shift at low fields reveals a decrease in spin susceptibility $χ_s$ consistent with singlet spin pairing. The field dependence of the spin-lattice relaxation rate at 100mK exhibits a sharp crossover (or phase transition) at a field $H_s\sim15$kOe, to a regime where $χ_s$ is close to the normal state value, even though \hc2 $\gg H_s$.

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J. Shinagawa, Y. Kurosaki, F. Zhang, C. Parker, S. E. Brown, D. Jerome, J. B. Christensen, K. Bechgaard. 2007-04-03. On the superconducting state of the organic conductor $(TMTSF)_2ClO_4$. https://arxiv.org/abs/cond-mat/0701566

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