One-directional polarization transport in electron/nuclear spin chains with loss and gain

Abstract

Understanding the joint dynamics of electron and nuclear spins is central to core concepts in solid-state magnetic resonance - such as spin-lattice relaxation and dynamic nuclear polarization - but a generalization that capitalizes on competing polarization loss and gain channels is still lacking. Here, we theoretically study the non-Hermitian dynamics of hybrid electron/nuclear spin systems in the simultaneous presence of electron spin pumping and spin-lattice relaxation. Focusing on periodic, one-dimensional chains, we find that by adjusting the electron spin pumping to a critical level, it is possible to steer the flow of nuclear polarization to create site-dependent distributions where either end of the array polarizes in opposite ways, irrespective of the initial state. By contrast, we show that ring-like patterns - where the limit nuclear polarization is uniform - exhibit a non-decaying, externally-driven nuclear spin current. Interestingly, cyclic magnetic field modulation can render these processes largely robust to defects in the chain, a response featuring some interesting similarities - and differences - with recent findings in other non-Hermitian physical platforms.

References in corpus (21)

• Nonreciprocal light transmission in parity-time-symmetric whispering-gallery microcavities
• QuTiP 2: A Python framework for the dynamics of open quantum systems
• Edge states and topological invariants of non-Hermitian systems
• Anomalous edge state in a non-Hermitian lattice
• Observation of bulk boundary correspondence breakdown in topolectrical circuits
• Observation of non-Hermitian bulk-boundary correspondence in quantum dynamics
• Efficient Light Funneling based on the non-Hermitian Skin Effect
• Anatomy of skin modes and topology in non-Hermitian systems
• Observation of non-Hermitian topology and its bulk-edge correspondence in an active mechanical metamaterial
• Transport and conservation laws
• Observation of parity-time symmetry breaking in a single spin system
• Optically addressable molecular spins for quantum information processing
• Topological states of non-Hermitian systems
• Molecular prototypes for spin-based CNOT quantum gates
• Non-equilibrium spin transport in integrable spin chains: persistent currents and emergence of magnetic domains
• Multi-spin-assisted optical pumping of bulk 13C nuclear spin polarization in diamond
• Energy Rectification in Quantum Graded Spin Chains: Analysis of the XXZ Model
• 13C dynamic nuclear polarization in diamond via a microwave-free 'integrated' cross effect
• Two-electron-spin ratchets as a platform for microwave-free dynamic nuclear polarization of arbitrary material targets
• Permanent Directional Heat Currents in Lattices of Optomechanical Resonators
• Magnetic-field-induced delocalization in hybrid electron-nuclear spin ensembles