Gapless quantum spin liquid in an organic spin-1/2 triangular-lattice κ-H3(Cat-EDT-TTF)2.
We report the results of SQUID and torque magnetometry of an organic spin-1/2 triangular-lattice κ-H(3)(Cat-EDT-TTF)(2). Despite antiferromagnetic exchange coupling at 80-100 K, we observed no sign of antiferromagnetic order down to 50 mK owing to spin frustration on the triangular lattice. In addition, we found nearly temperature-independent susceptibility below 3 K associated with Pauli paramagnetism. These observations suggest the development of gapless quantum spin liquid as the ground state. On the basis of a comparative discussion, we point out that the gapless quantum spin liquid states in organic systems share a possible mechanism, namely the formation of a band with a Fermi surface possibly attributed to spinons.
The Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Takayuki
T
Isono
The Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Hiromichi
H
Kamo
The Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Akira
A
Ueda
Department of Chemistry, Kobe University, Kobe, Hyogo 657-8501, Japan.
Kazuyuki
K
Takahashi
The Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Motoi
M
Kimata
The Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Hiroyuki
H
Tajima
National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan.
Satoshi
S
Tsuchiya
National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan.
Taichi
T
Terashima
National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan.
Shinya
S
Uji
The Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Hatsumi
H
Mori