Coupling conduction-band valleys in SiGe heterostructures via shear strain and Ge concentration oscillations
arXiv:2310.18879 · doi:10.1038/s41534-024-00853-6
Abstract
Engineering conduction-band valley couplings is a key challenge for Si-based spin qubits. Recent work has shown that the most reliable method for enhancing valley couplings entails adding Ge concentration oscillations to the quantum well. However, ultrashort oscillation periods are difficult to grow, while long oscillation periods do not provide useful improvements. Here, we show that the main benefits of short-wavelength oscillations can be achieved in long-wavelength structures through a second-order coupling process involving Brillouin-zone folding induced by shear strain. We finally show that such strain can be achieved through common fabrication techniques, making this an exceptionally promising system for scalable quantum computing.
13 pages (5 main text), 5 figures. Published version
References in corpus (19)
- Surface codes: Towards practical large-scale quantum computation
- Semiconductor Spin Qubits
- Computing with spin qubits at the surface code error threshold
- Fast universal quantum control above the fault-tolerance threshold in silicon
- A four-qubit germanium quantum processor
- Two-qubit silicon quantum processor with operation fidelity exceeding 99%
- A Reconfigurable Gate Architecture for Si/SiGe Quantum Dots
- Measurement of valley splitting in high-symmetry Si/SiGe quantum dots
- Atomic fluctuations lifting the energy degeneracy in Si/SiGe quantum dots
- SiGe quantum wells with oscillating Ge concentrations for quantum dot qubits
- Practical Strategies for Enhancing the Valley Splitting in Si/SiGe Quantum Wells
- Detuning Axis Pulsed Spectroscopy of Valley-Orbital States in Si/SiGe Quantum Dots
- How valley-orbit states in silicon quantum dots probe quantum well interfaces
- Enhanced Valley Splitting in Si Layers with Oscillatory Ge Concentration
- Spin-orbit enhancement in Si/SiGe heterostructures with oscillating Ge concentration
- Spin-Valley Qubit Dynamics In Exchange Coupled Silicon Quantum Dots
- Valley-Free Silicon Fins Caused by Shear Strain
- Engineering local strain for single-atom nuclear acoustic resonance in silicon
- Reducing strain fluctuations in quantum dot devices by gate-layer stacking
Cited by in corpus (5)
- Mapping of valley-splitting by conveyor-mode spin-coherent electron shuttling
- Theory of Valley Splitting in Si/SiGe Spin-Qubits: Interplay of Strain, Resonances and Random Alloy Disorder
- The effects of alloy disorder on strongly-driven flopping mode qubits in Si/SiGe
- Fabrication, characterization and mechanical loading of Si/SiGe membranes for spin qubit devices
- Exact Multi-Valley Envelope Function Theory of Valley Splitting in Si/SiGe Nanostructures