Quantitative Functional RG Approach to Spin Hamiltonians at Finite Temperatures
ORAL
Abstract
The pseudo-fermion functional renormalization group (pf-fRG) has been successfully applied to study frustrated magnets and identify several spin liquid candidates. It can be used to calculate momentum-resolved spin susceptibilities that can be directly compared to neutron scattering experiments. The method offers a straightforward way to implement infinite lattices with long-range interactions and complicated lattice geometries. However, its applicability has been limited to zero temperature. We develop a generalized pf-fRG method based on the Popov-Fedotov trick that produces quantitatively accurate results for spin Hamiltonians at finite temperature. We show that we can accurately detect finite-temperature phase-transitions by a finite size scaling approach and recover the correct critical exponents.
*The authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) for funding this project by providing computing time through the John von Neumann Institute for Computing (NIC) on the GCS Supercomputer JUWELS at Jülich Supercomputing Centre (JSC). The computations in this work were, in part, run at facilities supported by the Scientific Computing Core at the Flatiron Institute, a division of the Simons Foundation. The authors acknowledge financial support by a MCQST-START fellowship and by the Munich Quantum Valley, which is supported by the Bavarian state government with funds from the Hightech Agenda Bayern Plus.
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Publication: https://arxiv.org/abs/2209.13484
Presenters
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Benedikt Valentin Schneider
- Department of Physics, Ludwigs Maximilians University