Characterization and Suppression of Low-frequency Noise in Si/SiGe Quantum Point Contacts and Quantum Dots

Abstract

We report on the effects of a global top gate on low-frequency noise in Schottky gate-defined quantum point contacts (QPCs) and quantum dots (QDs) in a modulation-doped Si/SiGe heterostructure. For a relatively large top gate voltage, the QPC current shows frequent switching with 1/f2 Lorentzian type charge noise. As the top gate voltage is decreased, the QPC pinch-off voltage becomes less negative, and the 1/f2 noise becomes rapidly suppressed in a homogeneous background 1/f noise. We apply this top-gating technique to double QDs to stabilize the charge state for the electron number down to zero.

4 pages, 3 figures

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Cited by in corpus (16)

• 1/f noise: implications for solid-state quantum information
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• Three-electron spin qubits
• Optimal operation points for ultrafast, highly coherent Ge hole spin-orbit qubits
• Spin relaxation in a Si quantum dot due to spin-valley mixing
• Spin Relaxation due to Charge Noise
• Strong electron-electron interactions in Si/SiGe quantum dots
• Evaluating charge noise acting on semiconductor quantum dots in the circuit quantum electrodynamics architecture
• Do micromagnets expose spin qubits to charge and Johnson noise?
• Optimal geometry of lateral GaAs and Si/SiGe quantum dots for electrical control of spin qubits
• Phonon-assisted relaxation and decoherence of singlet-triplet qubits in Si/SiGe quantum dots
• Indications of a soft cutoff frequency in the charge noise of a Si/SiGe quantum dot spin qubit
• Characterization of a gate-defined double quantum dot in a Si/SiGe nanomembrane
• Optimisation of electrically-driven multi-donor quantum dot qubits
• Noise Correlations in a 1D Silicon Spin Qubit Array
• Nonadiabatic quantum control of quantum dot arrays with fixed exchange using Cartan decomposition