Gapless excitations in the ground state of 1T-TaS2
Gapless excitations in the ground state of 1T-TaS2
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DOI：
10.1103/physrevb.96.195131
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发表时间：
2017-11-15
影响因子：
3.7
通讯作者：
Kanigel, A.
中科院分区：
文献类型：
--
作者：
Ribak, A.;Silber, I.;Kanigel, A.
1T-TaS_2是一种层状过渡金属二卤化物，具有丰富的相图。在T=180K时，它经历了金属到Mott绝缘体的转变。MOTT绝缘体在绝缘相中通常表现出反铁磁有序，而1T-TaS_2则从未表现出磁性有序。本文证明了1T-TaS_2对磁化率有很大的顺磁贡献，但它没有表现出任何磁性有序或冻结到20mK的迹象，这可能表明它是一个量子自旋液体基态。尽管1T-TaS_2在低温下无论在面内还是在面外都表现出很强的电阻行为，我们在热容中发现了一个线性项，这表明费米面的存在，它具有反常的强磁场依赖性。
1T-TaS2 is a layered transition-metal dichalcogenide with a very rich phase diagram. At T = 180 K it undergoes a metal to Mott insulator transition. Mott insulators usually display antiferromagnetic ordering in the insulating phase but 1T-TaS2 was never shown to order magnetically. In this paper we show that 1T-TaS2 has a large paramagnetic contribution to the magnetic susceptibility but it does not show any sign of magnetic ordering or freezing down to 20 mK, as probed by muon spin relaxation, possibly indicating a quantum spin liquid ground state. Although 1T-TaS2 exhibits a strong resistive behavior both in and out of plane at low temperatures we find a linear term in the heat capacity suggesting the existence of a Fermi surface, which has an anomalously strong magnetic field dependence.