The Quantum pyrochlore $S=\frac{1}{2}$ Heisenberg antiferromagnet at finite and zero temperature
ORAL
Abstract
We use cutting-edge computational methods to investigate the pyrochlore $S=1/2$ antiferromagnet at finite and zero temperature.
By a systematic numerical high temperature expansion we gain insights into thermodynamic properties in the thermodynamic limit. Within the limit of convergence of our method ($T\approx 0.25J$) we establish a pronounced maximum in the specific heat at $T=0.57J$.
At zero temperature, we apply large scale $SU (2)$ DMRG to finite size clusters with up to 128 sites. Besides a precise determination of the ground state energy, $E_0 / N_{\text{sites}} = −0.49J$, our most striking finding is a robust spontaneous inversion symmetry breaking. This suggests a scenario in which a finite-temperature spin liquid regime gives way to an ordered state which breaks inversion symmetry spontaneously.
In a magnetic field, the pyrochlore antiferromagnet exhibits a nontrivial magnetization process which can host exotic magnetic phases. We find a particularly robust incompressible state reflected by a magnetization plateau at $\frac{1}{2}$ saturation. This state spontaneously breaks a different lattice symmetry compared to the zero field case: oppositely polarized spins on alternating kagome and triangular planes discard C_3 rotations.
By a systematic numerical high temperature expansion we gain insights into thermodynamic properties in the thermodynamic limit. Within the limit of convergence of our method ($T\approx 0.25J$) we establish a pronounced maximum in the specific heat at $T=0.57J$.
At zero temperature, we apply large scale $SU (2)$ DMRG to finite size clusters with up to 128 sites. Besides a precise determination of the ground state energy, $E_0 / N_{\text{sites}} = −0.49J$, our most striking finding is a robust spontaneous inversion symmetry breaking. This suggests a scenario in which a finite-temperature spin liquid regime gives way to an ordered state which breaks inversion symmetry spontaneously.
In a magnetic field, the pyrochlore antiferromagnet exhibits a nontrivial magnetization process which can host exotic magnetic phases. We find a particularly robust incompressible state reflected by a magnetization plateau at $\frac{1}{2}$ saturation. This state spontaneously breaks a different lattice symmetry compared to the zero field case: oppositely polarized spins on alternating kagome and triangular planes discard C_3 rotations.
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Publication: [1] Robin Schäfer, Imre Hagymási, Roderich Moessner, and David J. Luitz Phys. Rev. B 102, 054408<br>[2] Imre Hagymási, Robin Schäfer, Roderich Moessner, and David J. Luitz Phys. Rev. Lett. 126, 117204<br>[3] Imre Hagymási, Robin Schäfer, Roderich Moessner, and David J. Luitz arXiv:2106.09722
Presenters
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Robin Schaefer
Max Planck Institute for the Physics of Complex Systems
Authors
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Robin Schaefer
Max Planck Institute for the Physics of Complex Systems
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Imre Hagymási
Max Planck Institute for the Physics of Complex Systems
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David Luitz
Max Planck Institute for the Physics of Complex Systems
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Roderich Moessner
Max Planck Institute for the Physics of Complex Systems