Decoherence and fidelity enhancement during shuttling of entangled spin qubits

Abstract

Shuttling of spin qubits between different locations is a key element in many prospective semiconductor systems for quantum information processing, but the shuttled qubits should be protected from decoherence created by time- and space-dependent noises. Since the paths of different spin qubits are interrelated, the noises acting on the shuttled spins exhibit complex and unusual correlations. We appraise the role of these correlations using the concept of trajectories on random sheets, and demonstrate that they can drastically affect efficiency of the coherence protection. These correlations can also be exploited to enhance the shuttling fidelity, and we show that by encoding logical qubit in a state of two consequtively shuttled entangled spins, high fidelity can be achieved even for very slow shuttling. We identify the conditions favoring this encoding, and quantify improvement in the shuttling fidelity in comparison with the single-spin shuttling.

6 pages, 4 figures

References in corpus (26)

• Semiconductor Spin Qubits
• How to Enhance Dephasing Time in Superconducting Qubits
• Pure quantum dephasing of a solid state electron spin qubit in a large nuclear spin bath coupled by long-range hyperfine-mediated interactions
• Low-frequency spin qubit detuning noise in highly purified ${}^{28}$Si/SiGe
• Charge-noise spectroscopy of Si/SiGe quantum dots via dynamically-decoupled exchange oscillations
• Coherent spin qubit transport in silicon
• Conveyor-mode single-electron shuttling in Si/SiGe for a scalable quantum computing architecture
• A shuttling-based two-qubit logic gate for linking distant silicon quantum processors
• Operating semiconductor quantum processors with hopping spins
• Distant spin entanglement via fast and coherent electron shuttling
• Blueprint of a scalable spin qubit shuttle device for coherent mid-range qubit transfer in disordered Si/SiGe/SiO${}_2$
• The SpinBus Architecture: Scaling Spin Qubits with Electron Shuttling
• Noise-correlation spectrum for a pair of spin qubits in silicon
• Practical Strategies for Enhancing the Valley Splitting in Si/SiGe Quantum Wells
• Coherent spin qubit shuttling through germanium quantum dots
• Spin-EPR-pair separation by conveyor-mode single electron shuttling in Si/SiGe
• Spatial noise correlations beyond nearest-neighbor in ${}^{28}$Si/SiGe spin qubits
• Modelling semiconductor spin qubits and their charge noise environment for quantum gate fidelity estimation
• Enhanced spin coherence while displacing electron in a 2D array of quantum dots
• Mapping of valley-splitting by conveyor-mode spin-coherent electron shuttling
• Generation of a single-cycle acoustic pulse: a scalable solution for transport in single-electron circuits
• High-fidelity spin qubit shuttling via large spin-orbit interaction
• Characterization of individual charge fluctuators in Si/SiGe quantum dots
• Decoherence induced by a sparse bath of two-level fluctuators: peculiar features of $1/f$ noise in high-quality qubits
• Modelling of spin decoherence in a Si hole qubit perturbed by a single charge fluctuator
• Correlations of spin splitting and orbital fluctuations due to 1/f charge noise in the Si/SiGe Quantum Dot