TY - JOUR
T1 - Spin-lattice decoupling in a triangular-lattice quantum spin liquid
AU - Isono, Takayuki
AU - Sugiura, Shiori
AU - Terashima, Taichi
AU - Miyagawa, Kazuya
AU - Kanoda, Kazushi
AU - Uji, Shinya
N1 - Funding Information:
This work is partly supported by JSPS KAKENHI under grant numbers 15K05188, 17K05532, and 25220709. We thank M. Saito for technical assistance.
Publisher Copyright:
© 2018 The Author(s).
PY - 2018/12/1
Y1 - 2018/12/1
N2 - A quantum spin liquid (QSL) is an exotic state of matter in condensed-matter systems, where the electron spins are strongly correlated, but conventional magnetic orders are suppressed down to zero temperature because of strong quantum fluctuations. One of the most prominent features of a QSL is the presence of fractionalized spin excitations, called spinons. Despite extensive studies, the nature of the spinons is still highly controversial. Here we report magnetocaloric-effect measurements on an organic spin-1/2 triangular-lattice antiferromagnet, showing that electron spins are decoupled from a lattice in a QSL state. The decoupling phenomena support the gapless nature of spin excitations. We further find that as a magnetic field is applied away from a quantum critical point, the number of spin states that interact with lattice vibrations is strongly reduced, leading to weak spin-lattice coupling. The results are compared with a model of a strongly correlated QSL near a quantum critical point.
AB - A quantum spin liquid (QSL) is an exotic state of matter in condensed-matter systems, where the electron spins are strongly correlated, but conventional magnetic orders are suppressed down to zero temperature because of strong quantum fluctuations. One of the most prominent features of a QSL is the presence of fractionalized spin excitations, called spinons. Despite extensive studies, the nature of the spinons is still highly controversial. Here we report magnetocaloric-effect measurements on an organic spin-1/2 triangular-lattice antiferromagnet, showing that electron spins are decoupled from a lattice in a QSL state. The decoupling phenomena support the gapless nature of spin excitations. We further find that as a magnetic field is applied away from a quantum critical point, the number of spin states that interact with lattice vibrations is strongly reduced, leading to weak spin-lattice coupling. The results are compared with a model of a strongly correlated QSL near a quantum critical point.
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U2 - 10.1038/s41467-018-04005-1
DO - 10.1038/s41467-018-04005-1
M3 - Article
C2 - 29666404
AN - SCOPUS:85045734710
SN - 2041-1723
VL - 9
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 1509
ER -