An exactly solvable model for Dynamic Nuclear polarization

Abstract

We introduce a solvable model of driven fermions that elucidates the role of the localization transition in driven disordered magnets, as used in the context of dynamic nuclear polarization. Instead of spins, we study a set of non-interacting fermions that are coupled locally to nuclear spins and tend to hyperpolarize them. The induced hyperpolarization is a fingerprint of the driven steady state of the fermions, which undergo an Anderson Localization (AL) transition upon increasing the disorder. Our central result is that the maximal hyperpolarization level is always found close to the localization transition. In the limit of small nuclear moments the maximum is pinned to the transition, and the hyperpolarization is strongly enhanced by multi-fractal correlations in the critical state of the nearly localized driven system, its magnitude reflecting multi-fractal scaling.

11 pages, 6 figures, 5 pages of appendices

References in corpus (8)

• Anderson Transitions
• Many-body localization edge in the random-field Heisenberg chain
• Integrals of motion in the Many-Body localized phase
• Ergodicity breaking in a model showing many-body localization
• Thouless energy and multifractality across the many-body localization transition
• Localization phenomena in interacting Rydberg lattice gases with position disorder
• Dynamic nuclear polarization as kinetically constrained diffusion
• Eigenstate versus Zeeman-based approaches to the solid-effect

Cited by in corpus (4)

• Many-body localization: an introduction and selected topics
• Bath-induced Zeno localization in driven many-body quantum systems
• Cooling by photo-doping $--$ Light-induced symmetry breaking in the Hubbard model
• Unified understanding of the breakdown of thermal mixing dynamic nuclear polarization: the role of temperature and radical concentration