Eliminating Leakage Errors in Hyperfine Qubits

Abstract

Population leakage outside the qubit subspace presents a particularly harmful source of error that cannot be handled by standard error correction methods. Using a trapped ${}^{171}$Yb$+$ ion, we demonstrate an optical pumping scheme to suppress leakage errors in atomic hyperfine qubits. The selection rules and narrow linewidth of a quadrupole transition are used to selectively pump population out of leakage states and back into the qubit subspace. Each pumping cycle reduces the leakage population by a factor of $\sim 3$, allowing for an exponential suppression in the number of cycles. We use interleaved randomized benchmarking on the qubit subspace to show that this pumping procedure has negligible side-effects on un-leaked qubits, bounding the induced qubit memory error by $\le 2.0(8)\times 10^{-5}$ per cycle, and qubit population decay to $\le 1.4(3)\times 10^{-7}$ per cycle. These results clear a major obstacle for implementations of quantum error correction and error mitigation protocols.

arXiv comment4 pages, 4 figures

References in corpus (22)

• Experimental issues in coherent quantum-state manipulation of trapped atomic ions
• Error mitigation for short-depth quantum circuits
• 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
• High-fidelity preparation, gates, memory and readout of a trapped-ion quantum bit
• High-Fidelity Universal Gate Set for ${}^9$Be${}^{+}$ Ion Qubits
• Towards fault-tolerant quantum computing with trapped ions
• Hybrid Quantum-Classical Hierarchy for Mitigation of Decoherence and Determination of Excited States
• Manipulation and Detection of a Trapped Yb+ Ion Hyperfine Qubit
• Efficient measurement of quantum gate error by interleaved randomized benchmarking
• Long-lived qubit memory using atomic ions
• Single-qubit quantum memory exceeding $10$-minute coherence time
• Low-distance Surface Codes under Realistic Quantum Noise
• Low-cost error mitigation by symmetry verification
• Implementation of Grover's Quantum Search Algorithm in a Scalable System
• Errors in trapped-ion quantum gates due to spontaneous photon scattering
• Fault-tolerant quantum error detection
• Understanding the effects of leakage in superconducting quantum error detection circuits
• Comparing Zeeman qubits to hyperfine qubits in the context of the surface code: ${}^{174}$Yb${}^{+}$ and ${}^{171}$Yb${}^{+}$
• Probing Qubit Memory Errors at the Part-per-Million Level
• Randomized Benchmarking of Clifford Operators

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• All-microwave leakage reduction units for quantum error correction with superconducting transmon qubits
• A hardware-efficient leakage-reduction scheme for quantum error correction with superconducting transmon qubits
• A high fidelity light-shift gate for clock-state qubits
• Character randomized benchmarking for non-multiplicity-free groups with applications to subspace, leakage, and matchgate randomized benchmarking
• Fast Flux-Activated Leakage Reduction for Superconducting Quantum Circuits
• A Practical Introduction to Benchmarking and Characterization of Quantum Computers
• Robust population inversion in three-level systems by composite pulses
• Circuit-based leakage-to-erasure conversion in a neutral atom quantum processor
• Coupler-Assisted Leakage Reduction for Scalable Quantum Error Correction with Superconducting Qubits
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• Benchmarking quantum logic operations relative to thresholds for fault tolerance
• Characterizing quantum instruments: from non-demolition measurements to quantum error correction
• Randomized Benchmarking with Leakage Errors
• Logical Error Rates for the Surface Code Under a Mixed Coherent and Stochastic Circuit-Level Noise Model Inspired by Trapped Ions
• Error metric for non-trace-preserving quantum operations
• Experimental Demonstration of Swift Analytical Universal Control over Nearby Transitions
• Accurate Leakage Speculation for Quantum Error Correction
• Robust entanglement by continuous dynamical decoupling of the J-coupling interaction