Spin-Blockade Spectroscopy of Si/SiGe Quantum Dots

Abstract

We implement a technique for measuring the singlet-triplet energy splitting responsible for spin-to-charge conversion in semiconductor quantum dots. This method, which requires fast, single-shot charge measurement, reliably extracts an energy in the limits of both large and small splittings. We perform this technique on an undoped, accumulation-mode Si/SiGe triple-quantum dot and find that the measured splitting varies smoothly as a function of confinement gate biases. Not only does this demonstration prove the value of having an $insitu$ excited-state measurement technique as part of a standard tune-up procedure, it also suggests that in typical Si/SiGe quantum dot devices, spin-blockade can be limited by lateral orbital excitation energy rather than valley splitting.

arXiv comment18 pages, 9 figures

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Cited by in corpus (25)

• Semiconductor Spin Qubits
• Review of performance metrics of spin qubits in gated semiconducting nanostructures
• Quantum tomography of an entangled three-spin state in silicon
• Spiderweb array: A sparse spin-qubit array
• Radio-frequency detected fast charge sensing in undoped silicon quantum dots
• Quantifying error and leakage in an encoded Si/SiGe triple-dot qubit
• Rapid high-fidelity spin state readout in Si/SiGe quantum dots via radio-frequency reflectometry
• A flexible design platform for Si/SiGe exchange-only qubits with low disorder
• SiGe quantum wells with oscillating Ge concentrations for quantum dot qubits
• Adiabatic quantum state transfer in a semiconductor quantum-dot spin chain
• Fast and high-fidelity state preparation and measurement in triple-quantum-dot spin qubits
• Valley splittings in Si/SiGe quantum dots with a germanium spike in the silicon well
• 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
• Long-Distance Superexchange between Semiconductor Quantum-Dot Electron Spins
• Spin digitizer for high-fidelity readout of a cavity-coupled silicon triple quantum dot
• Mapping of valley-splitting by conveyor-mode spin-coherent electron shuttling
• Conditional Teleportation of Quantum-Dot Spin States
• Looped Pipelines Enabling Effective 3D Qubit Lattices in a Strictly 2D Device
• Resonant Exchange Operation in Triple-Quantum-Dot Qubits for Spin-Photon Transduction
• Cryogen-free scanning gate microscope for the characterization of Si/Si${}_{0.7}$Ge${}_{0.3}$ quantum devices at milli-Kelvin temperatures
• Coherent control of a triangular exchange-only spin qubit
• Measurement of tunnel coupling in a Si double quantum dot based on charge sensing
• Lifting of Spin Blockade by Charged Impurities in Si-MOS Double Quantum Dot Devices
• Gate reflectometry in dense quantum dot arrays