All-microwave leakage reduction units for quantum error correction with superconducting transmon qubits

Abstract

Minimizing leakage from computational states is a challenge when using many-level systems like superconducting quantum circuits as qubits. We realize and extend the quantum-hardware-efficient, all-microwave leakage reduction unit (LRU) for transmons in a circuit QED architecture proposed by Battistel et al. This LRU effectively reduces leakage in the second- and third-excited transmon states with up to $99\%$ efficacy in $220\mathrm{ns}$, with minimum impact on the qubit subspace. As a first application in the context of quantum error correction, we demonstrate the ability of multiple simultaneous LRUs to reduce the error detection rate and to suppress leakage buildup within $1\%$ in data and ancilla qubits over 50 cycles of a weight-2 parity measurement.

11 pages, 11 figures, 1 table; typos corrected

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Cited by in corpus (27)

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• Model-based Optimization of Superconducting Qubit Readout
• Fast Flux-Activated Leakage Reduction for Superconducting Quantum Circuits
• Reducing the error rate of a superconducting logical qubit using analog readout information
• Wafer-scale uniformity of Dolan-bridge and bridgeless Manhattan-style Josephson junctions for superconducting quantum processors
• Experimental error suppression in Cross-Resonance gates via multi-derivative pulse shaping
• Coupler-Assisted Leakage Reduction for Scalable Quantum Error Correction with Superconducting Qubits
• Efficient initialization of fluxonium qubits based on auxiliary energy levels
• Neural network decoder for near-term surface-code experiments
• Optimizing quantum error correction protocols with erasure qubits
• ERASER: Towards Adaptive Leakage Suppression for Fault-Tolerant Quantum Computing
• Multi-Purpose Architecture for Fast Reset and Protective Readout of Superconducting Qubits
• Surface Code with Imperfect Erasure Checks
• Balanced cross-Kerr coupling for superconducting qubit readout
• Above 99.9% Fidelity Single-Qubit Gates, Two-Qubit Gates, and Readout in a Single Superconducting Quantum Device
• Fast microwave-driven two-qubit gates between fluxonium qubits with a transmon coupler
• Multimode Purcell Filter for Superconducting-Qubit Reset and Readout with Intrinsic Purcell Protection
• Geometric Phase of a Transmon in a Dissipative Quantum Circuit
• Leakage Mobility in Superconducting Qubits as a Leakage Reduction Unit
• Accurate Leakage Speculation for Quantum Error Correction
• Optimal number of stabilizer measurement rounds in an idling surface code patch
• Entanglement generation in capacitively coupled Transmon-cavity system
• Passive leakage removal unit based on a disordered transmon array
• Logical operations with a dynamical qubit in Floquet-Bacon-Shor code
• Feedforward suppression of readout-induced faults in quantum error correction