TY  - CONF
AU  - Heinze, Leonie
AU  - Kotte, T.
AU  - Rausch, R.
AU  - Demuer, A.
AU  - Luther, S.
AU  - Feyerherm, R.
AU  - Ammerlaan, A. A. L. 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  - Quantum criticality and dimensional reduction in the frustrated sawtooth chain compound atacamite
M1  - FZJ-2025-04560
PY  - 2025
AB  - We present evidence for the presence of a field-induced quantum critical point (QCP) at 21.9(1) T (H || c axis) in the frustrated quantum magnet atacamite Cu$_2$Cl(OH)$_3$, a mineral which we have recently identified as a material realization of sawtooth chains [J ~ 336 K (basal-basal), J' ~ 102 K (basal-apical)]. Residual interchain couplings lead to long-range antiferromagnetic order in atacamite below $T_\mathrm{N}$ = 8.9(1) K. Through extensive high-field studies of the heat capacity, we were able to map the entropy landscape of atacamite up to 35 T. It features highly distorted isentropes indicative of quantum criticality in the material. By further combining macroscopic and microscopic high-field measurement techniques, we provide evidence for the QCP at 21.9(1) T to separate field regions with and without long-range magnetic order, but far away from full polarization of the material. Underpinned by numerical results we propose this behavior to be relatedto an effective dimensional reduction of the material, where the chains decouple into independent subunits. We interpret this behavior as a special type of dimensional reduction caused by the interchain network.
T2  - International Conference on Highly Frustrated Magnetism
CY  - 25 May 2025 - 30 May 2025, Toronto (Canada)
Y2  - 25 May 2025 - 30 May 2025
M2  - Toronto, Canada
LB  - PUB:(DE-HGF)6
UR  - https://juser.fz-juelich.de/record/1048338
ER  -