TY - JOUR
T1 - Phonon renormalization effects accompanying the 6 K anomaly in the quantum spin liquid candidate κ-(BEDT-TTF)2 Cu2(CN)3
AU - Matsuura, Masato
AU - Sasaki, Takahiko
AU - Naka, Makoto
AU - Müller, Jens
AU - Stockert, Oliver
AU - Piovano, Andrea
AU - Yoneyama, Naoki
AU - Lang, Michael
N1 - Funding Information:
We thank N. Sato and S. Sugiura for their help in preparating the experiments. The neutron experiments were performed with the approval of ILL (7-01-513) . This study was financially supported by Grants-in-Aid for Scientific Research (19H01833, 19K03723, 20H05144, and 22H04459) from the Japan Society for the Promotion of Science. This work was partly performed under the GIMRT Program of the Institute for Materials Research, Tohoku University (Proposals No. 202111-RDKGE-0004, No. 202112-RDKGE-0019, and No. 202012-RDKGE-0042). Work at Goethe University, Frankfurt, was supported by the Deutsche Forschungsgemeinschaft (DFG, German Science Foundation) for funding through TRR 288-422213477 (Project A06 and B02).
Publisher Copyright:
© 2022 authors. Published by the American Physical Society.
PY - 2022/10
Y1 - 2022/10
N2 - The low-temperature state of the quantum spin liquid candidate κ-(BEDT-TTF)2Cu2(CN)3 emerges via an anomaly at T∗∼6 K. Although signatures of this anomaly have been revealed in various quantities, its origin has remained unclear. Here we report inelastic neutron scattering measurements on single crystals of κ-(BEDT-TTF)2Cu2(CN)3, aiming at studying phonon renormalization effects at T∗. A drastic change was observed in the phonon damping across T∗ for a breathing mode of BEDT-TTF dimers at E=4.7 meV. The abrupt change in the phonon damping is attributed to a phase transition into a valence bond solid state based on an effective model describing the spin-charge coupling in this dimer-Mott system.
AB - The low-temperature state of the quantum spin liquid candidate κ-(BEDT-TTF)2Cu2(CN)3 emerges via an anomaly at T∗∼6 K. Although signatures of this anomaly have been revealed in various quantities, its origin has remained unclear. Here we report inelastic neutron scattering measurements on single crystals of κ-(BEDT-TTF)2Cu2(CN)3, aiming at studying phonon renormalization effects at T∗. A drastic change was observed in the phonon damping across T∗ for a breathing mode of BEDT-TTF dimers at E=4.7 meV. The abrupt change in the phonon damping is attributed to a phase transition into a valence bond solid state based on an effective model describing the spin-charge coupling in this dimer-Mott system.
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U2 - 10.1103/PhysRevResearch.4.L042047
DO - 10.1103/PhysRevResearch.4.L042047
M3 - Article
AN - SCOPUS:85144606503
SN - 2643-1564
VL - 4
JO - Physical Review Research
JF - Physical Review Research
IS - 4
M1 - L042047
ER -