Coherent rotations of qubits within a multi-species ion-trap quantum computer

Abstract

We describe, realize, and experimentally investigate a method to perform physical rotations of ion chains, trapped in a segmented surface Paul trap, as a building block for large scale quantum computational sequences. Control of trapping potentials is achieved by parametrizing electrode voltages in terms of spherical harmonic potentials. Voltage sequences that enable crystal rotations are numerically obtained by optimizing time-dependent ion positions and motional frequencies, taking into account the effect of electrical filters in our set-up. We minimize rotation-induced heating by expanding the sequences into Fourier components, and optimizing the resulting parameters with a machine-learning approach. Optimized sequences rotate ${}^{40}$Ca${}^{+}$ - ${}^{40}$Ca${}^{+}$ crystals with axial heating rates of $\Delta {\bar{n}}_{com}=0.6_{(-2)}^{(+3)}$ and $\Delta {\bar{n}}_{str}=3.9(5)$ phonons per rotation for the common and stretch modes, at mode frequencies of 1.24 and 2.15 MHz. Qubit coherence loss is 0.2(2)$\%$ per rotation. We also investigate rotations of mixed species crystals (${}^{40}$Ca${}^{+}$ - ${}^{88}$Sr${}^{+}$) and achieve unity success rate.

References in corpus (38)

• Quantum Computing
• Frequency Comparison of Two High-Accuracy Al+ Optical Clocks
• High-fidelity quantum logic gates using trapped-ion hyperfine qubits
• High-fidelity two-qubit quantum logic gates using trapped calcium-43 ions
• Heating of trapped ions from the quantum ground state
• High-Fidelity Universal Gate Set for ${}^9$Be${}^{+}$ Ion Qubits
• A microfabricated surface-electrode ion trap for scalable quantum information processing
• Ion-trap measurements of electric-field noise near surfaces
• A quantum information processor with trapped ions
• High-fidelity readout of trapped-ion qubits
• Single-qubit quantum memory exceeding $10$-minute coherence time
• Ground state laser cooling using electromagnetically induced transparency
• Coherent Diabatic Ion Transport and Separation in a Multi-Zone Trap Array
• Controlling fast transport of cold trapped ions
• Multi-Element Logic Gates for Trapped-Ion Qubits
• High fidelity transport of trapped-ion qubits through an X-junction trap array
• T-junction ion trap array for two-dimensional ion shuttling, storage and manipulation
• Assessing the progress of trapped-ion processors towards fault-tolerant quantum computation
• Colloquium: Trapped ions as quantum bits -- essential numerical tools
• Precise determination of micromotion for trapped-ion optical clocks
• Normal modes of trapped ions in the presence of anharmonic trap potentials
• Improved high-fidelity transport of trapped-ion qubits through a multi-dimensional array
• Decoherence Bounds on Quantum Computation with Trapped Ions
• Reliable transport through a microfabricated X-junction surface-electrode ion trap
• Preparation of Dicke States in an Ion Chain
• Phonon-phonon interactions due to non-linear effects in a linear ion trap
• Cryogenic setup for trapped ion quantum computing
• Microfabricated Ion Traps
• Experimental realization of fast ion separation in segmented Paul traps
• Ion traps fabricated in a CMOS foundry
• Heating and ion transport in a Y-junction surface-electrode trap
• Fast ion swapping for quantum information processing
• Measurement of Ion Motional Heating Rates over a Range of Trap Frequencies and Temperatures
• Deterministic reordering of 40Ca+ ions in a linear segmented Paul trap
• Dynamics and control of fast ion crystal splitting in segmented Paul traps
• 3D Sisyphus Cooling of Trapped Ions
• Optimum electrode configurations for fast ion separation in microfabricated surface ion traps
• Feedback-Optimized Operations with Linear Ion Crystals

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• Demonstration of two-dimensional connectivity for a scalable error-corrected ion-trap quantum processor architecture
• Inverse engineering of fast state transfer among coupled oscillators