TY  - JOUR
AU  - Heinze, Leonie
AU  - Kotte, T.
AU  - Rausch, R.
AU  - Demuer, A.
AU  - Luther, S.
AU  - Feyerherm, R.
AU  - Ammerlaan, E. L. Q. N.
AU  - Zeitler, U.
AU  - Gorbunov, D. I.
AU  - Uhlarz, M.
AU  - Rule, K. C.
AU  - Wolter, A. U. B.
AU  - Kühne, H.
AU  - Wosnitza, J.
AU  - Karrasch, C.
AU  - Süllow, S.
TI  - Atacamite Cu$_2$Cl(OH)$_3$ in High Magnetic Fields: Quantum Criticality and Dimensional Reduction of a Sawtooth-Chain Compound
JO  - Physical review letters
VL  - 134
IS  - 21
SN  - 0031-9007
CY  - College Park, Md.
PB  - APS
M1  - FZJ-2025-03247
SP  - 216701
PY  - 2025
AB  - We report an extensive high-field study of atacamite Cu$_2$⁢Cl⁢(OH)$_3$, a material realization of quantum sawtooth chains with weak interchain couplings, in continuous and pulsed magnetic fields up to 58 T. In particular, we have mapped the entropy landscape for fields as high as 35 T and have identified a field-induced quantum critical point at 21.9(1) T for H || c axis. The quantum critical point separates field regions with and without magnetic order, evidenced by our thermodynamic study and $^1$H nuclear magnetic resonance spectroscopy, but lies far below full saturation of the magnetization. Corroborated by numerical results using density-matrix renormalization group calculations, we find this behavior associated with a dimensional reduction of the spin system: the sawtooth chain effectively decouples into an antiferromagnetic spin-1/2 chain (backbone of the sawtooth chain) in the presence of an exchange field produced by the remaining field-polarized spins.
LB  - PUB:(DE-HGF)16
C6  - 40531025
UR  - <Go to ISI:>//WOS:001503644200008
DO  - DOI:10.1103/PhysRevLett.134.216701
UR  - https://juser.fz-juelich.de/record/1044510
ER  -