Coupling of quantum-dot states via elastic-cotunneling and crossed Andreev reflection in a minimal Kitaev chain

Abstract

Recently, exciting progress has been made in using the superconducting nanowires coupled to gate-defined quantum dots (QDs) to mimic the Kiteav chain and realize the Majorana-bound states via a poor man's route. The essential ingredient is to balance the interdot elastic-cotunneling (ECT) and crossed Andreev reflection (CAR). As theoretically proposed, this can be mediated by the Andreev bound states (ABSs) formed in the superconducting nanowires. However, most of the gate-tuning asymmetric features observed in experiments can not be captured using the current theoretical models. To address this insufficiency, here, we consider a full model that explicitly includes all the details of both the QD states and the ABSs. Remarkable agreement is found with the recent experimental observations, where our model correctly reveals the gate-tuning asymmetry in ECTs and by which the average QD state energy can also be extracted. In contrast, CARs do not depend on the tuning of QD states. Moreover, armed with the tunability of ECTs and CARs with QD states, we also predict a controllable anisotropic superexchange interaction between electron spins in the two separated QDs.

References in corpus (20)

• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Realization of a minimal Kitaev chain in coupled quantum dots
• Anomalous Josephson effect induced by spin-orbit interaction and Zeeman effect in semiconductor nanowires
• Parity qubits and poor man's Majorana bound states in double quantum dots
• Singlet and triplet Cooper pair splitting in hybrid superconducting nanowires
• Direct manipulation of a superconducting spin qubit strongly coupled to a transmon qubit
• Tunable superconducting coupling of quantum dots via Andreev bound states in semiconductor-superconductor nanowires
• Superconducting diode effect due to magnetochiral anisotropy in topological insulator and Rashba nanowires
• Roadmap towards Majorana qubits and nonabelian physics in quantum dot-based minimal Kitaev chains
• Controlled crossed Andreev reflection and elastic co-tunneling mediated by Andreev bound states
• Triplet correlations in Cooper pair splitters realized in a two-dimensional electron gas
• Spin Cross-Correlation Experiments in an Electron Entangler
• 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
• Minimal quantum dot based Kitaev chain with only local superconducting proximity effect
• High-fidelity two-qubit gates of hybrid superconducting-semiconducting singlet-triplet qubits
• Coupled superconducting spin qubits with spin-orbit interaction
• Microwave-assisted unidirectional superconductivity in Al-InAs nanowire-Al junctions under magnetic fields
• Spin-Orbit Interaction Enabled High-Fidelity Two-Qubit Gates

Cited by in corpus (10)

• Observation of edge and bulk states in a three-site Kitaev chain
• From perfect to imperfect poor man's Majoranas in minimal Kitaev chains
• Fate of poor man's Majoranas in the long Kitaev chain limit
• Scaling up a sign-ordered Kitaev chain without magnetic flux control
• A flux-controlled two-site Kitaev chain
• Braiding Majoranas in a linear quantum dot-superconductor array: Mitigating the errors from Coulomb repulsion and residual tunneling
• Properties and prevalence of false poor man's Majoranas in two- and three-site artificial Kitaev chains
• Revisiting the Poor Man's Majoranas: The Spin-Exchange Induced Spillover Effect
• Quantum capacitance and parity switching of a quantum-dot-based Kitaev chain
• Distinguishing Majorana bound states from accidental zero-energy modes with a microwave cavity