Lattice effects and entropy release at the low-temperature phase transition in the spin-liquid candidate kappa-(BEDT-TTF)2Cu2(CN)3.
作者： R. S. Manna , M. de Souza , A. Brühl , J. A. Schlueter , M. Lang
DOI: 10.1103/PHYSREVLETT.104.016403
关键词:
摘要: The spin-liquid candidate {kappa}-(BEDT-TTF){sub 2}Cu{sub 2}(CN){sub 3} has been studied by measuring the uniaxial expansion coefficients {alpha}{sub i}, specific heat, and magnetic susceptibility. Special emphasis was placed on mysterious anomaly around 6K - a potential instability. Distinct strongly anisotropic lattice effects have observed at 6K, clearly identifying this feature as second-order phase transition. Owing to large anomalies in application of Grueneisen scaling enabled us determine corresponding heat contribution entropy release. Comparison latter with available spin models suggests that degrees freedom alone cannot account for Scenarios, involving charge freedom, are discussed.
harvard.edu
arxiv.org
sci-hub.se 参考文章(32)
J. Müller, M. Lang, R. Helfrich, F. Steglich, T. Sasaki, High-resolution ac-calorimetry studies of the quasi-two- dimensional organic superconductor kappa-(BEDT- TTF)2Cu(NCS)2 Physical Review B. ,vol. 65, pp. 140509- 140509 ,(2002) , 10.1103/PHYSREVB.65.140509
Olexei I. Motrunich, Variational study of triangular lattice spin-1/2 model with ring exchanges and spin liquid state in kappa-(ET)2Cu2(CN)3 Physical Review B. ,vol. 72, pp. 045105- ,(2005) , 10.1103/PHYSREVB.72.045105
Tokutaro Komatsu, Nozomu Matsukawa, Takeharu Inoue, Gunzi Saito, None, Realization of Superconductivity at Ambient Pressure by Band-Filling Control in κ- (BEDT-TTF)2Cu2(CN)3 Journal of the Physical Society of Japan. ,vol. 65, pp. 1340- 1354 ,(1996) , 10.1143/JPSJ.65.1340
Mariano de Souza, Andreas Brühl, Jens Müller, Pascale Foury-Leylekian, Alec Moradpour, Jean-Paul Pouget, Michael Lang, Thermodynamic studies at the charge-ordering and spin-Peierls transitions in (TMTTF)2X Physica B-condensed Matter. ,vol. 404, pp. 494- 498 ,(2009) , 10.1016/J.PHYSB.2008.11.059
Hem C. Kandpal, Ingo Opahle, Yu-Zhong Zhang, Harald O. Jeschke, Roser Valentí, Revision of Model Parameters forκ-Type Charge Transfer Salts: AnAb InitioStudy Physical Review Letters. ,vol. 103, pp. 067004- ,(2009) , 10.1103/PHYSREVLETT.103.067004
Weihong Zheng, Rajiv R. P. Singh, Ross H. McKenzie, Radu Coldea, Temperature dependence of the magnetic susceptibility for triangular-lattice antiferromagnets with spatially anisotropic exchange constants Physical Review B. ,vol. 71, pp. 134422- ,(2005) , 10.1103/PHYSREVB.71.134422
C.L Broholm, R.J Cava, G.R Kowach, A.P Ramirez, Geometrical frustration, spin ice and negative thermal expansion – the physics of underconstraint Physica B-condensed Matter. ,vol. 280, pp. 290- 295 ,(2000) , 10.1016/S0921-4526(99)01695-6
G. Baskaran, Novel local symmetries and chiral-symmetry-broken phases in S=(1/2 triangular-lattice Heisenberg model Physical Review Letters. ,vol. 63, pp. 2524- 2527 ,(1989) , 10.1103/PHYSREVLETT.63.2524
Sung-Sik Lee, Patrick A. Lee, T. Senthil, Amperean Pairing Instability in the U(1) Spin Liquid State with Fermi Surface and Application to κ − ( BEDT − TTF ) 2 Cu 2 ( CN ) 3 Physical Review Letters. ,vol. 98, pp. 067006- ,(2007) , 10.1103/PHYSREVLETT.98.067006
Luca F. Tocchio, Alberto Parola, Claudius Gros, Federico Becca, Spin-liquid and magnetic phases in the anisotropic triangular lattice: The case of κ − ( ET ) 2 X Physical Review B. ,vol. 80, pp. 064419- ,(2009) , 10.1103/PHYSREVB.80.064419