Shinagawa J, Kurosaki Y, Zhang F, Parker C, Brown S E, Jérome D, Christensen J B, Bechgaard K
Department of Physics Astronomy, UCLA, Los Angeles, California 90095, USA.
Phys Rev Lett. 2007 Apr 6;98(14):147002. doi: 10.1103/PhysRevLett.98.147002.
(TMTSF)2ClO4 is a quasi-one-dimensional organic conductor and superconductor with Tc=1.4 K, and one of at least two Bechgaard salts observed to have upper critical fields far exceeding the paramagnetic limit. Nevertheless, the 77Se NMR Knight shift at low fields reveals a decrease in spin susceptibility chi(s) consistent with singlet spin pairing. The field dependence of the spin-lattice relaxation rate at 100 mK exhibits a sharp crossover (or phase transition) at a field Hs approximately 15 kOe, to a regime where chi(s) is close to the normal state value, even though Hc2>> Hs.
（TMTSF）₂ClO₄是一种临界温度Tc = 1.4 K的准一维有机导体和超导体，是观察到的至少两种上临界场远超过顺磁极限的贝加尔盐之一。然而，低场下的⁷⁷Se核磁共振奈特位移显示出自旋磁化率χ(s)降低，这与单重态自旋配对一致。在100 mK时自旋 - 晶格弛豫率的场依赖性在约15 kOe的场Hs处表现出尖锐的交叉（或相变），进入χ(s)接近正常态值的区域，尽管Hc2 >> Hs。
