Dzyaloshinskii-Moriya interactions in the SU(2) gauge theory of the Shastry-Sutherland Dirac spin liquids
Abstract
We classify the fermion bilinears of the SU(2) gauge theory of the Shastry-Sutherland Dirac spin liquids under the spin-orbit-locked space group and treat the Dzyaloshinskii-Moriya (DM) interactions of SrCu2(BO3)2 at leading order in 1/N and at one loop. At linear order DM can neither gap the spinons nor destabilize the SO(5) point above a scale T*. Symmetry forbids every local gauge-singlet fermion mass at any order. Among the singlet bilinears, the in-plane couplings induce only a conserved spin current of dimension exactly 2, which sets T*=4λ≃0.03-$0.17$ K, and the out-of-plane coupling only a flavored spin-2 current, irrelevant at a unitary critical point. DM-induced Yukawa couplings start below 2% of the one that bounds the pseudocritical window. In zero field, measured samples order above $1$ K, at or above T*. Below T*, in a two-dimensional sample at the critical pressure, the Dirac cones reconstruct into a chirally protected d-wave quadratic band touching whose only gauge-singlet gap channels are the two valence-bond components and the scalar chirality. A one-loop flow, with the gauge field screened by the band touching, ends at T**∼(0.03-0.1)λ on a ray containing valence-bond order for the material's exchange and for most random couplings, and otherwise on a gapped chiral ℤ2 spin liquid. The DM bias between the two plaquette patterns is at most of order 10−4, with a direction not fixed at O(1/N), whereas non-magnetic quenched disorder couples a relevant random field to the plaquette doublet and none to the chirality. A field along [100] induces a (π,π) Néel moment linear in the field; a field along [001] does not. This selection rule also holds in the dimer phase and is testable by 11B NMR under pressure.
Related
- Unifying Dirac spin liquids on square and Shastry–Sutherland lattices via fermionic deconfined criticality
- Dzyaloshinskii-Moriya interactions and deconfined criticality in SrCu2(BO3)2
- Is Herbertsmithite far from an ideal antiferromagnet? Ab-initio answer including in-plane Dzyaloshinskii-Moriya interactions and coupling with extra-plane impurities
- Quantum phase transitions and quantum-information characterization of a non-Hermitian XY chain with staggered Dzyaloshinskii--Moriya interactions
- Triplon thermal Hall response in a honeycomb-lattice J1-J2 Heisenberg antiferromagnet with Dzyaloshinskii--Moriya interactions
BibTeX
@misc{iqbal2026dzyaloshinskiimoriya,
title = {{Dzyaloshinskii-Moriya interactions in the SU(2) gauge theory of the Shastry-Sutherland Dirac spin liquids}},
author = {Yasir Iqbal},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.25082},
eprint = {2610.25082},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.25082},
}
RIS
TY - UNPB
TI - Dzyaloshinskii-Moriya interactions in the SU(2) gauge theory of the Shastry-Sutherland Dirac spin liquids
AU - Yasir Iqbal
PY - 2026
DA - 2026/10/18
PB - arXiv
DO - 10.48550/arxiv.2610.25082
UR - https://arxiv.org/abs/2610.25082
AB - We classify the fermion bilinears of the SU(2) gauge theory of the Shastry-Sutherland Dirac spin liquids under the spin-orbit-locked space group and treat the Dzyaloshinskii-Moriya (DM) interactions of SrCu_2(BO_3)_2 at leading order in 1/N and at one loop. At linear order DM can neither gap the spinons nor destabilize the SO(5) point above a scale T^*. Symmetry forbids every local gauge-singlet fermion mass at any order. Among the singlet bilinears, the in-plane couplings induce only a conserved spin current of dimension exactly 2, which sets T^*=4λ≃0.03-$0.17$ K, and the out-of-plane coupling only a flavored spin-2 current, irrelevant at a unitary critical point. DM-induced Yukawa couplings start below 2% of the one that bounds the pseudocritical window. In zero field, measured samples order above $1$ K, at or above T^*. Below T^*, in a two-dimensional sample at the critical pressure, the Dirac cones reconstruct into a chirally protected d-wave quadratic band touching whose only gauge-singlet gap channels are the two valence-bond components and the scalar chirality. A one-loop flow, with the gauge field screened by the band touching, ends at T^**∼(0.03-0.1)λ on a ray containing valence-bond order for the material's exchange and for most random couplings, and otherwise on a gapped chiral ℤ_2 spin liquid. The DM bias between the two plaquette patterns is at most of order 10^−4, with a direction not fixed at O(1/N), whereas non-magnetic quenched disorder couples a relevant random field to the plaquette doublet and none to the chirality. A field along [100] induces a (π,π) Néel moment linear in the field; a field along [001] does not. This selection rule also holds in the dimer phase and is testable by ^11B NMR under pressure.
ER -