Formation and Evolution of the Spin-Charge-Entangled Screening Cloud in the Majorana-Kondo System
arXiv:2511.16446
The paper investigates how a spin‑charge‑entangled screening cloud forms and evolves in a Majorana‑Kondo system, using numerical renormalization group calculations and temperature‑dependent correlation functions to reveal a crossover from two‑stage to simultaneous screening and its implications for detecting Majorana zero modes.
Abstract
Side-coupled Majorana zero modes in Kondo systems realize a simple yet nontrivial hybridization setup that leads to distinct physics from the conventional Kondo effect. We have demonstrated in a previous work that the system can be described by a spin-charge-entangled (SCE) quantum impurity model with an Andreevnormal boundary condition. Here we investigate in detail the formation process and microscopic mechanism of the SCE screening cloud using the numerical renormalization group method. We introduce temperature-dependent spatially integrated correlation functions that provide an unambiguous diagnostic of different components of the SCE screening cloud beyond the impurity entropy and local density of states. Our results reveal a crossover from a sequential two-stage screening of the spin and charge components to a simultaneous screening controlled by a single parameter. We also study the evolution of the low-energy fixed points in the presence of competing terms that break different symmetries and drive the system to different infrared fixed points. Our results suggest that the SCE screening effect in the Majorana-Kondo system makes itself a route to detecting Majorana zero modes.
12 pages, 4 figures