Noise-Protected Gate for Six-Electron Double-Dot Qubits

Abstract

Singlet-triplet spin qubits in six-electron double quantum dots, in moderate magnetic fields, can show superior immunity to charge noise. This immunity results from the symmetry of orbitals in the second energy shell of circular quantum dots: singlet and triplet states in this shell have identical charge distributions. Our phase-gate simulations, which include $1/f$ charge noise from fluctuating traps, show that this symmetry is most effectively exploited if the gate operation switches rapidly between sweet spots deep in the (3,3) and (4,2) charge stability regions; fidelities very close to one are predicted if subnanosecond switching can be performed.

7 pages, 3 figures

References in corpus (11)

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• Six-electron semiconductor double quantum dot qubits
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Cited by in corpus (14)

• Semiconductor Qubits In Practice
• Nonadiabatic Landau-Zener-Stückelberg-Majorana transitions, dynamics, and interference
• Coherence and Screening in Multi-Electron Spin Qubits
• Spin of a multielectron quantum dot and its interaction with a neighboring electron
• Two-Qubit Pulse Gate for the Three-Electron Double Quantum Dot Qubit
• Capacitively coupled singlet-triplet qubits in the double charge resonant regime
• Validity of the single-particle description and charge noise resilience for multielectron quantum dots
• Charge-noise tolerant exchange gates of singlet-triplet qubits in asymmetric double quantum dots
• Inverted Singlet-Triplet Qubit Coded on a Two-Electron Double Quantum Dot
• Charge-noise resilience of two-electron quantum dots in Si/SiGe heterostructures
• Robust entangling gate for capacitively coupled few-electron singlet-triplet qubits
• Preparation and Readout of Multielectron High-Spin States in a Gate-Defined GaAs/AlGaAs Quantum Dot
• Theory on electron-phonon spin dehphasing in GaAs multi-electron double quantum dots
• Exploring Entanglement Spectrum and Phase Diagram in multi-electron Quantum Dot Chains