Presence and absence of itinerant gapless excitations in the quantum spin liquid candidate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>EtMe</mml:mi></mml:mrow><mml:mn>3</mml:mn></mml:msub><mml:mrow><mml:mi>Sb</mml:mi><mml:msub><mml:mrow><mml:mo>[</mml:mo><mml:mi>Pd</mml:mi><mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi>dmit</mml:mi><mml:mo>)</mml:mo></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mo>]</mml:mo></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>
Minoru Yamashita, Yuki Sato, T. Tominaga, Y. Kasahara, S. Kasahara, Hongchang Cui, Reìzo Kato, T. Shibauchi, Yuji Matsuda
Abstract
The presence or absence of itinerant gapless excitations in the organic quantum spin liquid (QSL) candidate EtMe${}_{3}$Sb[Pd(dmit)${}_{2}$]${}_{2}$, probed by a finite residual linear term in the thermal conductivity ${\ensuremath{\kappa}}_{0}/T$, has been a controversial hot topic. Here, the authors find that ${\ensuremath{\kappa}}_{0}/T$ strongly depends on the cooling process. A finite ${\ensuremath{\kappa}}_{0}/T$ is observed in a slowly cooled sample, but not in a rapidly cooled sample. These results provide evidence that the true ground state of EtMe${}_{3}$Sb[Pd(dmit)${}_{2}$]${}_{2}$ is a QSL with itinerant gapless excitations.