Effect of quantum Hall edge strips on valley splitting in silicon quantum wells

Abstract

We determine the energy splitting of the conduction-band valleys in two-dimensional electrons confined to low-disorder Si quantum wells. We probe the valley splitting dependence on both perpendicular magnetic field $B$ and Hall density by performing activation energy measurements in the quantum Hall regime over a large range of filling factors. The mobility gap of the valley-split levels increases linearly with $B$ and is strikingly independent of Hall density. The data are consistent with a transport model in which valley splitting depends on the incremental changes in density $eB/h$ across quantum Hall edge strips, rather than the bulk density. Based on these results, we estimate that the valley splitting increases with density at a rate of 116 $\mu$eV/10${}^{11}$cm${}^{-2}$, consistent with theoretical predictions for near-perfect quantum well top interfaces.

References in corpus (33)

• Silicon Quantum Electronics
• An addressable quantum dot qubit with fault-tolerant control fidelity
• A Two Qubit Logic Gate in Silicon
• A >99.9%-fidelity quantum-dot spin qubit with coherence limited by charge noise
• A programmable two-qubit quantum processor in silicon
• Interfacing spin qubits in quantum dots and donors - hot, dense and coherent
• Quantum CNOT Gate for Spins in Silicon
• Silicon quantum processor unit cell operation above one Kelvin
• Universal quantum logic in hot silicon qubits
• Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting
• Scalable gate architecture for densely packed semiconductor spin qubits
• Exchange in silicon-based quantum computer architecture
• A Crossbar Network for Silicon Quantum Dot Qubits
• Controllable valley splitting in silicon quantum devices
• Silicon qubit fidelities approaching incoherent noise limits via pulse engineering
• Valley Splitting Theory of SiGe/Si/SiGe Quantum Wells
• A Reconfigurable Gate Architecture for Si/SiGe Quantum Dots
• Low disordered, stable, and shallow germanium quantum wells: a playground for spin and hybrid quantum technology
• The Observation of Percolation-Induced 2D Metal-Insulator Transition in a Si MOSFET
• Electrically Protected Valley-Orbit Qubits in Silicon
• Measurement of valley splitting in high-symmetry Si/SiGe quantum dots
• Large, tunable valley splitting and single-spin relaxation mechanisms in a Si/Si${}_x$Ge${}_{1-x}$ quantum dot
• High Resolution Valley Spectroscopy of Si Quantum Dots
• The Two-flux Composite Fermion Series of Fractional Quantum Hall States in Strained Si
• Tunable singlet-triplet splitting in a few-electron Si/SiGe quantum dot
• Single-Spin Relaxation in a Synthetic Spin-Orbit Field
• Valley dependent anisotropic spin splitting in silicon quantum dots
• Disorder-induced valley-orbit hybrid states in Si quantum dots
• Multiplexed quantum transport using commercial off-the-shelf CMOS at sub-kelvin temperatures
• The critical role of substrate disorder in valley splitting in Si quantum wells
• Dressed photon-orbital states in a quantum dot: Inter-valley spin resonance
• Well-width dependence of valley splitting in Si/SiGe quantum wells
• Compressed Optimization of Device Architectures (CODA) for semiconductor quantum devices

Cited by in corpus (9)

• 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
• Mapping of valley-splitting by conveyor-mode spin-coherent electron shuttling
• Wafer-scale low-disorder 2DEG in ${}^{28}$Si/SiGe without an epitaxial Si cap
• Spin-Valley Qubit Dynamics In Exchange Coupled Silicon Quantum Dots
• Origin of giant valley splitting in silicon quantum wells induced by superlattice barriers
• Valley splitting in silicon from the interference pattern of quantum oscillations
• Charge noise suppression in capacitively coupled singlet-triplet spin qubits under magnetic field
• Density dependence of the excitation gaps in an undoped Si/SiGe double-quantum-well heterostructure