Multiple quantum phase transitions of different nature in the topological kagome magnet Co₃Sn_2−xIn_xS₂

TY - JOUR

T1 - Multiple quantum phase transitions of different nature in the topological kagome magnet Co3Sn2−xInxS2

AU - Guguchia, Z.

AU - Zhou, H.

AU - Wang, C. N.

AU - Yin, J. X.

AU - Mielke, C.

AU - Tsirkin, S. S.

AU - Belopolski, I.

AU - Zhang, S. S.

AU - Cochran, T. A.

AU - Neupert, T.

AU - Khasanov, R.

AU - Amato, A.

AU - Jia, S.

AU - Hasan, M. Z.

AU - Luetkens, H.

N1 - Publisher Copyright: © 2021, The Author(s).

PY - 2021/12

Y1 - 2021/12

N2 - The exploration of topological electronic phases that result from strong electronic correlations is a frontier in condensed matter physics. One class of systems that is currently emerging as a platform for such studies are so-called kagome magnets based on transition metals. Using muon spin-rotation, we explore magnetic correlations in the kagome magnet Co3Sn2−xInxS2 as a function of In-doping, providing putative evidence for an intriguing incommensurate helimagnetic (HM) state. Our results show that, while the undoped sample exhibits an out-of-plane ferromagnetic (FM) ground state, at 5% of In-doping the system enters a state in which FM and in-plane antiferromagnetic (AFM) phases coexist. At higher doping, a HM state emerges and becomes dominant at the critical doping level of only xcr,1 ≃ 0.3. This indicates a zero temperature first order quantum phase transition from the FM, through a mixed state, to a helical phase at xcr,1. In addition, at xcr,2 ≃ 1, a zero temperature second order phase transition from helical to paramagnetic phase is observed, evidencing a HM quantum critical point (QCP) in the phase diagram of the topological magnet Co3Sn2−xInxS2. The observed diversity of interactions in the magnetic kagome lattice drives non-monotonous variations of the topological Hall response of this system.

AB - The exploration of topological electronic phases that result from strong electronic correlations is a frontier in condensed matter physics. One class of systems that is currently emerging as a platform for such studies are so-called kagome magnets based on transition metals. Using muon spin-rotation, we explore magnetic correlations in the kagome magnet Co3Sn2−xInxS2 as a function of In-doping, providing putative evidence for an intriguing incommensurate helimagnetic (HM) state. Our results show that, while the undoped sample exhibits an out-of-plane ferromagnetic (FM) ground state, at 5% of In-doping the system enters a state in which FM and in-plane antiferromagnetic (AFM) phases coexist. At higher doping, a HM state emerges and becomes dominant at the critical doping level of only xcr,1 ≃ 0.3. This indicates a zero temperature first order quantum phase transition from the FM, through a mixed state, to a helical phase at xcr,1. In addition, at xcr,2 ≃ 1, a zero temperature second order phase transition from helical to paramagnetic phase is observed, evidencing a HM quantum critical point (QCP) in the phase diagram of the topological magnet Co3Sn2−xInxS2. The observed diversity of interactions in the magnetic kagome lattice drives non-monotonous variations of the topological Hall response of this system.

UR - https://www.scopus.com/pages/publications/85106258960

UR - https://www.scopus.com/pages/publications/85106258960#tab=citedBy

U2 - 10.1038/s41535-021-00352-3

DO - 10.1038/s41535-021-00352-3

M3 - Article

SN - 2397-4648

VL - 6

JO - npj Quantum Materials

JF - npj Quantum Materials

IS - 1

M1 - 50

ER -