All-electrical manipulation of silicon spin qubits with tunable spin-valley mixing

Abstract

We show that the mixing between spin and valley degrees of freedom in a silicon quantum bit (qubit) can be controlled by a static electric field acting on the valley splitting $\Delta$. Thanks to spin-orbit coupling, the qubit can be continuously switched between a spin mode (where the quantum information is encoded into the spin) and a valley mode (where the the quantum information is encoded into the valley). In the spin mode, the qubit is more robust with respect to inelastic relaxation and decoherence, but is hardly addressable electrically. It can however be brought into the valley mode then back to the spin mode for electrical manipulation. This opens new perspectives for the development of robust and scalable, electrically addressable spin qubits on silicon. We illustrate this with tight-binding simulations on a so-called "corner dot" in a silicon-on-insulator device where the confinement and valley splitting can be independently tailored by a front and a back gate.

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• Electric-field control and noise protection of the flopping-mode spin qubit
• A silicon singlet-triplet qubit driven by spin-valley coupling
• Variability of electron and hole spin qubits due to interface roughness and charge traps
• Effects of Interface Steps on the Valley Orbit coupling in a Si/SiGe quantum dot
• Towards scalable silicon quantum computing
• Two-body Wigner molecularization in asymmetric quantum dot spin qubits
• Electric-field tuning of the valley splitting in silicon corner dots
• Hole-phonon interactions in quantum dots: Effects of phonon confinement and encapsulation materials on spin-orbit qubits
• Bounds to electron spin qubit variability for scalable CMOS architectures
• A Spin Quintet in a Silicon Double Quantum Dot: Spin Blockade and Relaxation
• All-Electrical Control of an Electron Spin/Valley Quantum Bit in SOI CMOS Technology
• Charge qubit in van der Waals heterostructures
• Electrical operation of hole spin qubits in planar MOS silicon quantum dots
• Modelling of spin decoherence in a Si hole qubit perturbed by a single charge fluctuator
• All-Electrical Control of a Hybrid Electron Spin/Valley Quantum Bit in SOI CMOS Technology
• Cancelling second order frequency shifts in Ge hole spin qubits via bichromatic control