Universal logic with encoded spin qubits in silicon

Abstract

Qubits encoded in a decoherence-free subsystem and realized in exchange-coupled silicon quantum dots are promising candidates for fault-tolerant quantum computing. Benefits of this approach include excellent coherence, low control crosstalk, and configurable insensitivity to certain error sources. Key difficulties are that encoded entangling gates require a large number of control pulses and high-yielding quantum dot arrays. Here we show a device made using the single-layer etch-defined gate electrode architecture that achieves both the required functional yield needed for full control and the coherence necessary for thousands of calibrated exchange pulses to be applied. We measure an average two-qubit Clifford fidelity of $97.1\pm 0.2\%$ with randomized benchmarking. We also use interleaved randomized benchmarking to demonstrate the controlled-NOT gate with $96.3\pm 0.7\%$ fidelity, SWAP with $99.3\pm 0.5\%$ fidelity, and a specialized entangling gate that limits spreading of leakage with $93.8\pm 0.7\%$ fidelity.

References in corpus (13)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Randomized Benchmarking of Quantum Gates
• Universal control of a six-qubit quantum processor in silicon
• Electrometry Using Coherent Exchange Oscillations in a Singlet-Triplet-Qubit
• Two-qubit silicon quantum processor with operation fidelity exceeding 99%
• Quantum error correction with silicon spin qubits
• Electron spin decoherence in isotope-enriched silicon
• SiGe quantum wells with oscillating Ge concentrations for quantum dot qubits
• Fast and high-fidelity state preparation and measurement in triple-quantum-dot spin qubits
• Programmable quantum simulations of bosonic systems with trapped ions
• Hyperfine-Induced Decay in Triple Quantum Dots
• A new FDSOI spin qubit platform with 40nm effective control pitch
• Full-permutation dynamical decoupling in triple-quantum-dot spin qubits

Cited by in corpus (58)

• Semiconductor Spin Qubits
• Universal control of a six-qubit quantum processor in silicon
• Probing single electrons across 300 mm spin qubit wafers
• Operating semiconductor quantum processors with hopping spins
• The SpinBus Architecture: Scaling Spin Qubits with Electron Shuttling
• Colloquium: Advances in automation of quantum dot devices control
• Assessment of error variation in high-fidelity two-qubit gates in silicon
• 12-spin-qubit arrays fabricated on a 300 mm semiconductor manufacturing line
• Universal control of four singlet-triplet qubits
• A 300 mm foundry silicon spin qubit unit cell exceeding 99% fidelity in all operations
• Hotter is easier: unexpected temperature dependence of spin qubit frequencies
• Rapid single-shot parity spin readout in a silicon double quantum dot with fidelity exceeding 99 %
• Braiding-based quantum control of a Majorana qubit built from quantum dots
• Utilizing multimodal microscopy to reconstruct Si/SiGe interfacial atomic disorder and infer its impacts on qubit variability
• Tuning arrays with rays: Physics-informed tuning of quantum dot charge states
• Coherent control of a triangular exchange-only spin qubit
• Cavity-mediated entanglement of parametrically driven spin qubits via sidebands
• Microwave-frequency scanning gate microscopy of a Si/SiGe double quantum dot
• Compromise-Free Scaling of Qubit Speed and Coherence
• Decay-protected superconducting qubit with fast control enabled by integrated on-chip filters
• Dynamically Generated Decoherence-Free Subspaces and Subsystems on Superconducting Qubits
• Modular Autonomous Virtualization System for Two-Dimensional Semiconductor Quantum Dot Arrays
• Single-step high-fidelity three-qubit gates by anisotropic chiral interactions
• Autonomous Bootstrapping of Quantum Dot Devices
• Flip-chip-based fast inductive parity readout of a planar superconducting island
• Tunable p-n junction barriers in few-electron bilayer graphene quantum dots
• Noise Correlations in a 1D Silicon Spin Qubit Array
• Randomized Benchmarking with Leakage Errors
• Highly tunable 2D silicon quantum dot array with coupling beyond nearest neighbors
• Theory of charge stability diagrams in coupled quantum dot qubits
• A spinless spin qubit
• Valley Splitting Correlations Across a Silicon Quantum Well Containing Germanium
• Swapping Floquet time crystal
• Experimental online quantum dots charge autotuning using neural networks
• Mitigation of exchange cross-talk in dense quantum dot arrays
• Operating two exchange-only qubits in parallel
• A 2x2 quantum dot array in silicon with fully tuneable pairwise interdot coupling
• Latched readout for the quantum dot hybrid qubit
• Quantum Computation by Spin Parity Measurements with Encoded Spin Qubits
• All-electrical operation of a spin qubit coupled to a high-Q resonator
• Pauli Spin Blockade in a Resonant Triple Quantum Dot Molecule
• Single-shot latched readout of a quantum dot qubit using barrier gate pulsing
• Minimal evolution times for fast, pulse-based state preparation in silicon spin qubits
• A diverse set of two-qubit gates for spin qubits in semiconductor quantum dots
• Electrical readout of spins in the absence of spin blockade
• Correcting on-chip distortion of control pulses with silicon spin qubits
• Variational quantum compiling for three-qubit gates design in quantum dots
• Second Quantization: Gating a Quantum Dot Through the Sequential Removal of Single Electrons from a Nanoscale Floating Gate
• Singlet-only Always-on Gapless Exchange Qubits with Baseband Control
• Direct measurement of spin-flip rates in single-electron tunneling
• Compilation Techniques for Spin Qubits in a Shuttling Bus Architecture
• Dressed basis sets for the modeling of exchange interactions in double quantum dots
• Negative exchange interaction in Si quantum dot arrays via valley-phase induced ${\mathbb{Z}}_2$ gauge field
• Inverse exciton spin orientation due to trion formation in modulation doped quantum wells
• Jenga-Krotov algorithm: Efficient compilation of multi-qubit gates for exchange-only qubits
• Limitations on the maximal level of entanglement of two singlet-triplet qubits in GaAs quantum dots
• Spin qubit shuttling between coupled quantum dots with inhomogeneous Landé g-tensors
• Robust composite two-qubit gates for silicon-based spin qubits