Absence of Magnetic Thermal Conductivity in the Quantum Spin Liquid Candidate EtMe_{3}Sb[Pd(dmit)_{2}]_{2}

J M Ni; B L Pan; B Q Song; Y Y Huang; J Y Zeng; Y J Yu; E J Cheng; L S Wang; D Z Dai; R Kato; S Y Li

doi:10.1103/PhysRevLett.123.247204

Absence of Magnetic Thermal Conductivity in the Quantum Spin Liquid Candidate EtMe_{3}Sb[Pd(dmit)_{2}]_{2}

Phys Rev Lett. 2019 Dec 13;123(24):247204. doi: 10.1103/PhysRevLett.123.247204.

Authors

J M Ni¹, B L Pan¹, B Q Song¹, Y Y Huang¹, J Y Zeng¹, Y J Yu¹, E J Cheng¹, L S Wang¹, D Z Dai¹, R Kato², S Y Li^{1

3}

Affiliations

¹ State Key Laboratory of Surface Physics, Department of Physics, and Laboratory of Advanced Materials, Fudan University, Shanghai 200438, China.
² RIKEN, Condensed Molecular Materials Laboratory, Wako 351-0198, Japan.
³ Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.

PMID: 31922852
DOI: 10.1103/PhysRevLett.123.247204

Abstract

We present the ultralow-temperature specific heat and thermal conductivity measurements on single crystals of triangular-lattice compound EtMe_{3}Sb[Pd(dmit)_{2}]_{2}, which has long been considered as a gapless quantum spin liquid candidate. In specific heat measurements, a finite linear term is observed, consistent with the previous work [S. Yamashita et al., Nat. Commun. 2, 275 (2011)NCAOBW2041-172310.1038/ncomms1274]. However, we do not observe a finite residual linear term in the thermal conductivity measurements, and the thermal conductivity does not change in a magnetic field of 6 T. These results are in sharp contrast to previous thermal conductivity measurements on EtMe_{3}Sb[Pd(dmit)_{2}]_{2} [M. Yamashita et al., Science 328, 1246 (2010)SCIEAS0036-807510.1126/science.1188200], in which a huge residual linear term was observed and attributed to highly mobile gapless excitations, likely the spinons of a quantum spin liquid. In this context, the true ground state of EtMe_{3}Sb[Pd(dmit)_{2}]_{2} has to be reconsidered.