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arXiv · 2112.10215

Heisenberg spins on an anisotropic triangular lattice: PdCrO2 under uniaxial stress

Dan Sun·Dmitry A. Sokolov·Richard Waite·Seunghyun Khim·Pascal Manuel·Fabio Orlandi·Dmitry D. Khalyavin·Andrew P. Mackenzie·Clifford W. Hicks
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Abstract

When Heisenberg spins interact antiferromagnetically on a triangular lattice and nearest-neighbor interactions dominate, the ground state is 120$^{\circ}$ antiferromagnetism. In this work, we probe the response of this state to lifting the triangular symmetry, through investigation of the triangular antiferromagnet PdCrO$_2$ under uniaxial stress by neutron diffraction and resistivity measurements. The periodicity of the magnetic order is found to change rapidly with applied stress; the rate of change indicates that the magnetic anisotropy is roughly forty times the stress-induced bond length anisotropy. At low stress, the incommensuration period becomes extremely long, on the order of 1000 lattice spacings; no locking of the magnetism to commensurate periodicity is detected. Separately, the magnetic structure is found to undergo a first-order transition at a compressive stress of $\sim$0.4 GPa, at which the interlayer ordering switches from a double- to a single-q structure.

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Dan Sun, Dmitry A. Sokolov, Richard Waite, Seunghyun Khim, Pascal Manuel, Fabio Orlandi, Dmitry D. Khalyavin, Andrew P. Mackenzie, Clifford W. Hicks. 2021-12-19. Heisenberg spins on an anisotropic triangular lattice: PdCrO2 under uniaxial stress. https://doi.org/10.1088/1367-2630%2Fac4280

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