Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2406.09271

Spin excitations in Nd1-xSrxNiO2 and YBa2Cu3O7-delta: the influence of Hubbard U

Francesco Rosa·Leonardo Martinelli·Guillaume Krieger·Lucio Braicovich·Nicholas B. Brookes·Giacomo Merzoni·Marco Moretti Sala·Flora Yakhou-Harris·Riccardo Arpaia·Daniele Preziosi·Marco Salluzzo·Maciej Fidrysiak·Giacomo Ghiringhelli
View original source ↗Read source document ↗Export metadata ↓

Abstract

We use Resonant Inelastic X-ray Scattering (RIXS) to compare the doping dependence of magnetic excitations of an Infinite-Layer nickelate to those of a prototypical superconducting cuprate. The polarization analysis of RIXS spectra establishes the dominant spin-flip nature of the mid-infrared peak in both cases. Hole doping leads to opposite behavior of the magnetic energy in the two materials. By fitting the data with an original Hubbard-based model for dynamic susceptibility, we find that t is comparable in the two materials while U is about twice larger in the nickelate. This finding accounts for the smaller magnetic bandwidth of nickelates and for its decrease upon doping.

Explore related subjects

cond-mat.str-elquant-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Francesco Rosa, Leonardo Martinelli, Guillaume Krieger, Lucio Braicovich, Nicholas B. Brookes, Giacomo Merzoni, Marco Moretti Sala, Flora Yakhou-Harris, Riccardo Arpaia, Daniele Preziosi, Marco Salluzzo, Maciej Fidrysiak, Giacomo Ghiringhelli. 2024-06-13. Spin excitations in Nd1-xSrxNiO2 and YBa2Cu3O7-delta: the influence of Hubbard U. https://arxiv.org/abs/2406.09271

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Discernible signatures of fractionally charged anyons in a Pfaffian-Laughlin state

Understanding the nature of quasihole excitations, i.e., anyons that have fractional charge and fractional statistics, has been a challenging problem in condensed matter physics. Our theoretical approach to this problem has been to consider a quantum dot containing a few charged particles, Coulomb coupled to the incompressible fluid. The size of the dot and the separation distance of the dot from the incompressible state strongly influences the energetics of the Laughlin quasiholes. Photoluminescence (PL) spectroscopy studies of this system have previously been able to probe these quasiholes that have confirmed our estimates of the Laughlin quasihole energies. Turning to the Pfaffian state, we now observe that such a theoretical approach is also able to provide valuable information about the Pfaffian quasiholes, viz., the energy dispersion, the charge density distribution and the quasihole energy. The energy dispersion of e/4 quasiholes derived here, clearly reflect the interaction between the quantum dot and the incompressible Pfaffian state. PL spectroscopy experiments on the 5/2 Pfaffian-Laughlin state could perhaps shed light on the energetics we found here of these elusive quasiparticles.

cond-mat.str-el↗
arXiv2026

Algebras of order parameters in one-dimensional spin systems

We study order parameters in one-dimensional quantum lattice models with finite invertible or non-invertible symmetry. We investigate what properties a string operator must satisfy in order to acquire a non-vanishing expectation value in a given gapped phase. We deduce that multiplets of string order parameters organise into a Lagrangian algebra in the Drinfel'd centre of the symmetry category. In particular, we highlight the role of the multiplication rule as governing the fusion of the twisted sector local operators that constitute the string operator in the infrared limit. Our derivations exploit the tensor network approach to the classification of gapped phases and its reformulation in terms of module categories over the symmetry category. Within this framework, a gapped phase is associated with a pattern of spontaneous symmetry breaking wherein a Morita class of algebras of topological lines is preserved in the ground state subspace. The crux of the proof is to show that the expectation value of any string operator explicitly depends on the tube algebra module associated with the Lagrangian algebra, which is realised as the full centre of the corresponding module category. Finally, we demonstrate that these techniques extend to phases of symmetric mixed states.

cond-mat.str-el↗
arXiv2026

Sign-problem-resilient singular-value probe in determinant quantum Monte Carlo

The sign problem limits determinant quantum Monte Carlo studies of strongly correlated fermion systems. In the spin-channel Hubbard-Stratonovich decoupling, spin correlations are exactly related to auxiliary-field correlations. This relation implies that an antiferromagnetic transition reorganizes auxiliary-field configurations and thereby changes the statistical structure of the resulting fermion matrices. We use the adjacent gap ratio of low-lying singular values of the space-time fermion matrix to probe interaction-driven transitions in two half-filled honeycomb-lattice Hubbard models. In the sign-free honeycomb Hubbard model, the statistic tracks the established transition from a Dirac semimetal to an antiferromagnetic Mott insulator. In the complex-weight Haldane-Hubbard model, the transition-sensitive feature remains visible in the phase-quenched reference ensemble and occurs near previous estimates of the transition. Moreover, phase reweighting only weakly modifies the gap ratio over the regimes investigated, despite the rapid suppression of the average phase. These results establish singular-value statistics as a sign-problem-resilient probe of interaction-driven transitions in determinant quantum Monte Carlo.

cond-mat.str-el↗