Spectral damping without quasiparticle decay: The dynamic structure factor of two-dimensional quantum Heisenberg antiferromagnets

Abstract

Two-dimensional Heisenberg antiferromagnets play a central role in quantum magnetism, yet the nature of dynamic correlations in these systems at finite temperature has remained poorly understood for decades. We solve this long-standing problem by using a novel quantum-classical duality to calculate the dynamic structure factor analytically and, paradoxically, find a broad frequency spectrum despite the very long quasiparticle lifetime. The solution reveals new multi-scale physics whereby an external probe creates a classical radiation field containing infinitely-many quanta. Crucially, it is the multi-scale nature of this phenomenon which prevents a conventional renormalization group approach. We also challenge the common wisdom on static correlations and perform Monte Carlo simulations which demonstrate excellent agreement with our theory.

arXiv comment13 pages, 7 figures, 1 table

References in corpus (6)

• Quantum Spin Liquids
• Neutron tomography of magnetic Majorana fermions in a proximate quantum spin liquid
• Theory of Two-Dimensional Quantum Heisenberg Antiferromagnets with a Nearly Critical Ground State
• Resonant inelastic X-ray scattering response of the Kitaev honeycomb model
• Colossal quasiparticle radiation in the Lifshitz spin liquid phase of a two-dimensional quantum antiferromagnet
• Anomalous thermal broadening from an infrared catastrophe in two-dimensional quantum antiferromagnets

Cited by in corpus (1)

• The non-analytic momentum dependence of spin susceptibility of Heisenberg magnets in paramagnetic phase and its effect on critical exponents