Spin-Charge-Entangled Kondo Effect Induced by a Side-Coupled Majorana Zero Mode

We investigate Kondo physics in a quantum dot side-coupled to a Majorana zero mode, where the Majorana coupling induces both spin and charge fluctuations that determine low-energy behavior. Using a wavefunction-based Schrieffer-Wolff transformation combined with numerical renormalization group calculations, we discover a novel $SU_L(2)$ spin-charge-entangled Kondo state, in which conduction electrons screen the spin-charge-entangled degrees of freedom of the Majorana-quantum dot subsystem. We show that the parity degeneracy of this state gives rise to spin-resolved Andreev-normal boundary conditions, resulting in non-Fermi-liquid behavior. Density matrix renormalization group simulations directly resolve a hallmark of these boundary conditions - a subleading even-odd effect in the screening cloud. Our framework bridges strongly correlated and topological phenomena, and naturally extends to $\mathbb{Z}_N$ parafermions and $SU(N)$ Kondo systems.