Coherent multi-spin exchange coupling in a quantum-dot spin chain

Abstract

Heisenberg exchange coupling between neighboring electron spins in semiconductor quantum dots provides a powerful tool for quantum information processing and simulation. Although so far unrealized, extended Heisenberg spin chains can enable long-distance quantum information transfer and the generation of non-equilibrium quantum states. In this work, we implement simultaneous, coherent exchange coupling between all nearest-neighbor pairs of spins in a quadruple quantum dot. The main challenge in implementing simultaneous exchange couplings is the nonlinear and nonlocal dependence of the exchange couplings on gate voltages. Through a combination of electrostatic simulation and theoretical modeling, we show that this challenge arises primarily due to lateral shifts of the quantum dots during gate pulses. Building on this insight, we develop two models, which can be used to predict the confinement gate voltages for a desired set of exchange couplings. Although the model parameters depend on the number of exchange couplings desired (suggesting that effects in addition to lateral wavefunction shifts are important), the models are sufficient to enable simultaneous and independent control of all three exchange couplings in a quadruple quantum dot. We demonstrate two-, three-, and four-spin exchange oscillations, and our data agree with simulations.

9+10 pages, 5+5 figures

References in corpus (48)

• Quantum Computation with Quantum Dots
• The many-body localization phase transition
• Quantum Communication Through an Unmodulated Spin Chain
• Universal Quantum Computation with the Exchange Interaction
• Quantum CNOT Gate for Spins in Silicon
• Quantum Communication through Spin Chain Dynamics: an Introductory Overview
• Universal quantum control of two-electron spin quantum bits using dynamic nuclear polarization
• Quantum simulation of a Fermi-Hubbard model using a semiconductor quantum dot array
• Rapid Single-Shot Measurement of a Singlet-Triplet Qubit
• Scalable gate architecture for densely packed semiconductor spin qubits
• Fast Single-Charge Sensing with an rf Quantum Point Contact
• Reduced sensitivity to charge noise in semiconductor spin qubits via symmetric operation
• Quantum control and process tomography of a semiconductor quantum dot hybrid qubit
• Coherent electronic transfer in quantum dot systems using adiabatic passage
• Shuttling a single charge across a one-dimensional array of silicon quantum dots
• Coherent spin manipulation in an exchange-only qubit
• Self-Consistent Measurement and State Tomography of an Exchange-Only Spin Qubit
• Noise suppression using symmetric exchange gates in spin qubits
• A fast "hybrid" silicon double quantum dot qubit
• Fast sensing of double-dot charge arrangement and spin state with an rf sensor quantum dot
• Differential Charge Sensing and Charge Delocalization in a Tunable Double Quantum Dot
• A Reconfigurable Gate Architecture for Si/SiGe Quantum Dots
• Single-Spin CCD
• Loading a quantum-dot based "Qubyte" register
• Coherent spin state transfer via Heisenberg exchange
• Efficient multiqubit entanglement via a spin-bus
• Coherent spin-exchange via a quantum mediator
• A 2x2 quantum dot array with controllable inter-dot tunnel couplings
• Automated tuning of inter-dot tunnel couplings in quantum dot arrays
• Adiabatic Gate Teleportation
• Site-selective quantum control in an isotopically enriched 28Si/SiGe quadruple quantum dot
• Charge-noise-insensitive gate operations for always-on, exchange-only qubits
• Computer-automated tuning procedures for semiconductor quantum dot arrays
• Enhanced charge detection of spin qubit readout via an intermediate state
• Fast spin exchange between two distant quantum dots
• Heisenberg Spin Bus as a Robust Transmission Line for Perfect State Transfer
• Efficient orthogonal control of tunnel couplings in a quantum dot array
• Protocol for a resonantly-driven three-qubit Toffoli gate with silicon spin qubits
• Tunable coupling and isolation of single electrons in silicon metal-oxide-semiconductor quantum dots
• A quadrupolar exchange-only spin qubit
• Readout Of Singlet-Triplet Qubits At Large Magnetic Field Gradients
• Effect of an inhomogeneous external magnetic field on a quantum dot quantum computer
• The exchange-only singlet-only spin qubit
• Resonant Exchange Operation in Triple-Quantum-Dot Qubits for Spin-Photon Transduction
• Stabilization and manipulation of multispin states in quantum-dot time crystals with Heisenberg interactions
• Highly tunable exchange-only singlet-only qubit in a GaAs triple quantum dot
• Noise-induced collective quantum state preservation in spin qubit arrays
• Compressed Optimization of Device Architectures (CODA) for semiconductor quantum devices

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• Single-preparation unsupervised quantum machine learning: concepts and applications
• Coherent transport of spin by adiabatic passage in quantum dot arrays
• Emergence and Dynamical Stability of Charge Time-Crystal in a Current-Carrying Quantum Dot Simulator
• Two dimensional vertex-decorated Lieb lattice with exact mobility edges and robust flat bands
• Thermodynamic Uncertainty Relations for Coherent Transport
• Automated extraction of capacitive coupling for quantum dot systems
• Optimal Control in Disordered Quantum Systems
• Dynamically corrected gates in silicon singlet-triplet spin qubits
• Approaching ideal visibility in singlet-triplet qubit operations using energy-selective tunneling-based Hamiltonian estimation
• Modular Autonomous Virtualization System for Two-Dimensional Semiconductor Quantum Dot Arrays
• Low-Dissipation Data Bus via Coherent Quantum Dynamics
• Mitigation of exchange cross-talk in dense quantum dot arrays
• Sign-switching of superexchange mediated by few electrons under non-uniform magnetic field
• Multi-qubit DC gates over an inhomogeneous array of quantum dots
• Protecting coherence from the environment via Stark many-body localization in a Quantum-Dot Simulator
• Universal control of superexchange in linear triple quantum dots with an empty mediator
• Pauli Spin Blockade in a Resonant Triple Quantum Dot Molecule
• Shortcut to spin dynamics for quantum mixtures
• Jenga-Krotov algorithm: Efficient compilation of multi-qubit gates for exchange-only qubits