Optimal control of a cavity-mediated iSWAP gate between silicon spin qubits
arXiv:2208.11151 · doi:10.1103/PhysRevApplied.18.064082
Abstract
Semiconductor spin qubits may be coupled through a superconducting cavity to generate an entangling two-qubit gate. However, the fidelity of such an operation will be reduced by a variety of error mechanisms such as charge and magnetic noise, phonons, cavity loss, transitions to non-qubit states and, for electrons in silicon, excitation into other valley eigenstates. Here, we model the effects of these error sources and the valley degree of freedom on the performance of a cavity-mediated two-qubit iSWAP gate. For valley splittings inadequately large relative to the interdot tunnel coupling within each qubit, we find that valley excitation may be a limiter to the fidelity of this two-qubit gate. In addition, we show tradeoffs between gating times and exposure to various error sources, identifying optimal operating regimes and device improvements that would have the greatest impact on the fidelity of the cavity-mediated spin iSWAP. Importantly, we find that while the impact of charge noise and phonon relaxation favor operation in the regime where the qubits are most spin-like to reduce sensitivity to these sources of noise, the combination of hyperfine noise and valley physics shifts the optimal regime to charge-like qubits with stronger effective spin-photon coupling so that gate times can be made as short as possible. In this regime, the primary limitation is the need to avoid Landau-Zener transitions as the gate is implemented.
References in corpus (56)
- Quantum Computation with Quantum Dots
- A Quantum Engineer's Guide to Superconducting Qubits
- Manipulating the Quantum State of an Electrical Circuit
- A >99.9%-fidelity quantum-dot spin qubit with coherence limited by charge noise
- Coherent manipulation of electronic states in a double quantum dot
- Interfacing spin qubits in quantum dots and donors - hot, dense and coherent
- Electrically driven single electron spin resonance in a slanting Zeeman field
- Computing with spin qubits at the surface code error threshold
- Electrical control of a long-lived spin qubit in a Si/SiGe quantum dot
- Fast universal quantum control above the fault-tolerance threshold in silicon
- Circuit Quantum Electrodynamics with a Spin Qubit
- A Coherent Spin-Photon Interface in Silicon
- Strong spin-photon coupling in silicon
- Fidelity benchmarks for two-qubit gates in silicon
- Two-qubit silicon quantum processor with operation fidelity exceeding 99%
- Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting
- Scalable gate architecture for densely packed semiconductor spin qubits
- Coherent spin-qubit photon coupling
- Strong Coupling Cavity QED with Gate-Defined Double Quantum Dots Enabled by a High Impedance Resonator
- Long-Range Microwave Mediated Interactions Between Electron Spins
- Coherent coupling of a single spin to microwave cavity photons
- Silicon qubit fidelities approaching incoherent noise limits via pulse engineering
- Nonadiabatic Landau-Zener-Stückelberg-Majorana transitions, dynamics, and interference
- Valley Splitting Theory of SiGe/Si/SiGe Quantum Wells
- Benchmarking Gate Fidelities in a Si/SiGe Two-Qubit Device
- Coherent spin-spin coupling mediated by virtual microwave photons
- Quantum tomography of an entangled three-spin state in silicon
- Input-output theory for spin-photon coupling in Si double quantum dots
- Interface roughness, valley-orbit coupling and valley manipulation in quantum dots
- Electron spin resonance and spin-valley physics in a silicon double quantum dot
- Electrically Protected Valley-Orbit Qubits in Silicon
- Measurement of valley splitting in high-symmetry Si/SiGe quantum dots
- Coherent transfer of quantum information in silicon using resonant SWAP gates
- Large, tunable valley splitting and single-spin relaxation mechanisms in a Si/SiGe quantum dot
- High Resolution Valley Spectroscopy of Si Quantum Dots
- Optimized cavity-mediated dispersive two-qubit gates between spin qubits
- Charge Relaxation in a Single Electron Si/SiGe Double Quantum Dot
- Microwave photon-mediated interactions between semiconductor qubits
- Quantum dot spin qubits in Silicon: Multivalley physics
- A flexible design platform for Si/SiGe exchange-only qubits with low disorder
- Single-Spin Relaxation in a Synthetic Spin-Orbit Field
- Multicore Quantum Computing
- Coupling a single electron spin to a microwave resonator: Controlling transverse and longitudinal couplings
- Dispersive readout of valley splittings in cavity-coupled silicon quantum dots
- Orbital and valley state spectra of a few-electron silicon quantum dot
- Giant anisotropy of spin relaxation and spin-valley mixing in a silicon quantum dot
- A silicon singlet-triplet qubit driven by spin-valley coupling
- Flopping-mode electric dipole spin resonance
- Detuning Axis Pulsed Spectroscopy of Valley-Orbital States in Si/SiGe Quantum Dots
- Enhancing coherent energy transfer between quantum devices via a mediator
- The critical role of substrate disorder in valley splitting in Si quantum wells
- Long-distance entangling gates between quantum dot spins mediated by a superconducting resonator
- On-chip microwave filters for high-impedance resonators with gate-defined quantum dots
- Probing the Spatial Variation of the Inter-Valley Tunnel Coupling in a Silicon Triple Quantum Dot
- Magnetic Gradient Fluctuations from Quadrupolar Ge in Si/SiGe Exchange-Only Qubits
- Split-Gate Cavity Coupler for Silicon Circuit Quantum Electrodynamics