Revisiting the Poor Man's Majoranas: The Spin-Exchange Induced Spillover Effect
arXiv:2509.05088 · doi:10.1088/1361-648X/ae2f13
Abstract
We give a review on Poor Man's Majorana (PMM) modes, which are theoretically established in the minimal Kitaev chain implementation consisting of two grounded, spinless quantum dots (QDs) operating at the sweet spot condition, where electron cotunneling and crossed Andreev reflection amplitudes achieve precise balance. Particularly, we systematically review, within the Green's functions theoretical framework, the PMM hybridization dynamics under spin-exchange perturbations proposed by some of us in J. Phys.: Condens. Matter 37, 205601 (2025), which demonstrates a characteristic spatial delocalization when subjected to an exchange coupling mediated by a quantum spin . This spin-exchange induced PMM spillover effect provides a spectroscopic protocol for determining the quantum statistics of through the emergent multi-level structure in the proximal QD's density of states. Our principal theoretical result establishes that the exchange interaction generates () satellite states symmetrically distributed about the zero-bias anomaly, serving as a definitive signature of bosonic (fermionic) spin statistics. As novelty, we demonstrate that multi-terminal environmental coupling induces significant suppression of the spin-exchange spillover mechanism. Under constrained variations of , this effectively localizes the perturbed PMM within its host QD, preventing spatial hybridization with adjacent site. The absence of topological protection in this minimal Kitaev realization is strategically leveraged to: (i) Develop a novel spectroscopic technique for quantum spin characterization through PMM hybridization signatures; (ii) Propose the "environmentally induced protection", an engineered dissipative spectral stabilization for PMMs against exchange fluctuations in multi-terminal architectures.
References in corpus (33)
- Non-Abelian Anyons and Topological Quantum Computation
- Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
- Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
- Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
- Majorana bound states in a coupled quantum-dot hybrid-nanowire system
- Introduction to topological superconductivity and Majorana fermions
- Scaling of Majorana Zero-Bias Conductance Peaks
- Realization of a minimal Kitaev chain in coupled quantum dots
- Distinguishing a Majorana zero mode using spin resolved measurements
- Parity qubits and poor man's Majorana bound states in double quantum dots
- Controlled length-dependent interaction of Majorana modes in Yu-Shiba-Rusinov chains
- Majorana nanowires for topological quantum computation
- A two-site Kitaev chain in a two-dimensional electron gas
- Roadmap towards Majorana qubits and nonabelian physics in quantum dot-based minimal Kitaev chains
- Robust poor man's Majorana zero modes using Yu-Shiba-Rusinov states
- Crossed Andreev reflection and elastic co-tunneling in a three-site Kitaev chain nanowire device
- Probing Majorana localization in minimal Kitaev chains through a quantum dot
- Fusion protocol for Majorana modes in coupled quantum dots
- Signatures of Majorana protection in a three-site Kitaev chain
- Observation of edge and bulk states in a three-site Kitaev chain
- Braiding-based quantum control of a Majorana qubit built from quantum dots
- Fermion-parity qubit in a proximitized double quantum dot
- From perfect to imperfect poor man's Majoranas in minimal Kitaev chains
- Fate of poor man's Majoranas in the long Kitaev chain limit
- Coupling of quantum-dot states via elastic-cotunneling and crossed Andreev reflection in a minimal Kitaev chain
- Non-Hermitian minimal Kitaev chains
- Majorana sweet spots in 3-site Kitaev chains
- Spin-resolved spectroscopy using a quantum dot defined in InAs 2DEG
- Spin-filtered measurements of Andreev bound states
- Emergent pair symmetries in systems with poor man's Majorana modes
- Spin-Exchange Induced Spillover on Poor Man's Majoranas in Minimal Kitaev Chains
- Exchangeless braiding of Majorana zero modes in weakly coupled Kitaev chains
- Properties and prevalence of false poor man's Majoranas in two- and three-site artificial Kitaev chains