Fingerprints of supersymmetric spin and charge dynamics observed by inelastic neutron scattering

• DOI: 10.48550/arxiv.2408.12626
• Publication Date: 2024-08-19
• Authors: Björn Wehinger; F. T. Lisandrini; Noam Kestin; Pierre Bouillot; Simon Ward; D. Biner; Robert Bewley; Karl W. Krämer; B. Normand; C. Kollath; T. Giamarchi; Andreas M. Läuchli; Christian Rüegg
• Keywords: Neutron spin echo; Quasielastic neutron scattering; Dynamics

Supersymmetry is an algebraic property of a class quantum Hamiltonians, guiding principle used in the development nuclear theory and concept that may underpin physics beyond Standard Model. In condensed matter, any symmetry between bosonic fermionic entities usually strongly broken, as for spin charge sectors $t$-$J$ model describing dynamics fractionalized electrons one-dimensional materials. While triplet excitations ladder applied magnetic field provide close analogue chain, supersymmetric nature this system has not been explored. Here we perform neutron spectroscopy on spin-ladder compounds (C$_5$D$_{12}$N)$_2$CuBr$_4$ (C$_5$D$_{12}$N)$_2$CuCl$_4$ over range fields temperatures, apply matrix-product-state (MPS) methods to equivalent chain models, analyse full, momentum-resolved single excitation bath spins. We find dramatic difference effects thermal fluctuations, where strong coherent shifts spectral weight at zone edge contrast with strict pole centre, whose persistence all temperatures constitutes observable consequence supersymmetry ladder.