Novel permanent magnet array geometries for scalable trapped-ion quantum computing in a laser-free entanglement architecture

Abstract

A novel design is presented for a permanent magnet array to address specific challenges with scalable trapped-ion quantum computing systems. Design and optimization of this magnet geometry is motivated by concepts for large-scale Quantum Charge-Coupled Device (QCCD) architectures. This proposal is relevant to magnetic field gradient schemes for laser-free entanglement using long-wavelength radiation, and individual addressing based on spatially dependent, magnetic field sensitive qubits. This configuration generates a localized, asymmetric magnetic field, yielding a region for ion transport into and out of a strong magnetic field gradient, while minimizing the absolute field experienced by the ion. This is a distinct improvement for scalability over dipolar magnet geometries where a strong magnetic field surrounds a magnetic field nil in three dimensions, which is problematic for ion transport applications. The design also relaxes the alignment constraints for experimental setup by allowing greater tolerance to misalignment in two dimensions. Additionally, the potential to scale a permanent magnet scheme in QCCD systems circumvents engineering challenges associated with using large electrical currents to generate the field gradient. Finally, a conceptual discussion is given for incorporating the design into a scalable QCCD type architecture.

28 pages, 13 figures

References in corpus (27)

• Superconducting Qubits: Current State of Play
• Trapped-Ion Quantum Computing: Progress and Challenges
• Demonstration of a small programmable quantum computer with atomic qubits
• High-fidelity two-qubit quantum logic gates using trapped calcium-43 ions
• High-fidelity quantum logic gates using trapped-ion hyperfine qubits
• Elucidating Reaction Mechanisms on Quantum Computers
• Large Scale Modular Quantum Computer Architecture with Atomic Memory and Photonic Interconnects
• How to factor 2048 bit RSA integers in 8 hours using 20 million noisy qubits
• High-fidelity preparation, gates, memory and readout of a trapped-ion quantum bit
• Quantum computing with neutral atoms
• Ion-trap quantum logic using long-wavelength radiation
• Realization of an Error-Correcting Surface Code with Superconducting Qubits
• Single ion-qubit exceeding one hour coherence time
• High-rate, high-fidelity entanglement of qubits across an elementary quantum network
• Blueprint for a microwave trapped-ion quantum computer
• Trapped-ion quantum logic gates based on oscillating magnetic fields
• High-fidelity laser-free universal control of two trapped ion qubits
• Errors in trapped-ion quantum gates due to spontaneous photon scattering
• Improved Fault-Tolerant Quantum Simulation of Condensed-Phase Correlated Electrons via Trotterization
• Individual addressing of trapped ions and coupling of motional and spin states using rf radiation
• Trapped-ion quantum logic with global radiation fields
• A high-fidelity quantum matter-link between ion-trap microchip modules
• Designing spin-spin interactions with one and two dimensional ion crystals in planar micro traps
• Generation of spin-motion entanglement in a trapped ion using long-wavelength radiation
• An ultra-stable 1.5 tesla permanent magnet assembly for qubit experiments at cryogenic temperatures
• A planar ion trap chip with integrated structures for an adjustable magnetic field gradient
• Fabrication of Surface Ion Traps with Integrated Current Carrying Wires enabling High Magnetic Field Gradients