How valley-orbit states in silicon quantum dots probe quantum well interfaces

Abstract

The energies of valley-orbit states in silicon quantum dots are determined by an as yet poorly understood interplay between interface roughness, orbital confinement, and electron interactions. Here, we report measurements of one- and two-electron valley-orbit state energies as the dot potential is modified by changing gate voltages, and we calculate these same energies using full configuration interaction calculations. The results enable an understanding of the interplay between the physical contributions and enable a new probe of the quantum well interface.

9 pages, 5 figures

References in corpus (8)

• Scalable gate architecture for densely packed semiconductor spin qubits
• Excited-state spectroscopy on a nearly-closed quantum dot via charge detection
• Measurement of valley splitting in high-symmetry Si/SiGe quantum dots
• Magnetic field dependence of valley splitting in realistic Si/SiGe quantum wells
• Spin filling of valley-orbit states in a silicon quantum dot
• Orbital and valley state spectra of a few-electron silicon quantum dot
• Strong electron-electron interactions in Si/SiGe quantum dots
• Valley splittings in Si/SiGe quantum dots with a germanium spike in the silicon well

Cited by in corpus (23)

• Atomic fluctuations lifting the energy degeneracy in Si/SiGe quantum dots
• Blueprint of a scalable spin qubit shuttle device for coherent mid-range qubit transfer in disordered Si/SiGe/SiO${}_2$
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• Practical Strategies for Enhancing the Valley Splitting in Si/SiGe Quantum Wells
• Colloquium: Advances in automation of quantum dot devices control
• Valley splittings in Si/SiGe quantum dots with a germanium spike in the silicon well
• Low disorder and high valley splitting in silicon
• Coherent spin-valley oscillations in silicon
• Mapping of valley-splitting by conveyor-mode spin-coherent electron shuttling
• Utilizing multimodal microscopy to reconstruct Si/SiGe interfacial atomic disorder and infer its impacts on qubit variability
• Strategies for enhancing spin-shuttling fidelities in Si/SiGe quantum wells with random-alloy disorder
• Microwave-frequency scanning gate microscopy of a Si/SiGe double quantum dot
• Coupling conduction-band valleys in SiGe heterostructures via shear strain and Ge concentration oscillations
• Atomistic compositional details and their importance for spin qubits in isotope-purified silicon-germanium quantum wells
• Valleytronic full configuration-interaction approach: An application to the excitation spectra of Si double-dot qubits
• Charge-noise resilience of two-electron quantum dots in Si/SiGe heterostructures
• Valley Splitting Correlations Across a Silicon Quantum Well Containing Germanium
• Latched readout for the quantum dot hybrid qubit
• Micromagnet-free operation of electron spin qubits in Si/Si${}_{1-x}$Ge${}_x$ vertical double quantum dots
• Omnidirectional shuttling to avoid valley excitations in Si/SiGe quantum wells
• Dressed basis sets for the modeling of exchange interactions in double quantum dots
• The effects of alloy disorder on strongly-driven flopping mode qubits in Si/SiGe
• Towards Utilizing Scanning Gate Microscopy as a High-Resolution Probe of Valley Splitting in Si/SiGe Heterostructures