Quantum dots in Si/SiGe 2DEGs with Schottky top-gated leads

Abstract

We report on the fabrication and characterization of quantum dot devices in a Schottky-gated silicon/silicon-germanium two-dimensional electron gas (2DEG). The dots are confined laterally inside an etch-defined channel, while their potential is modulated by an etch-defined 2DEG gate in the plane of the dot. For the first time in this material, Schottky top gates are used to define and tune the tunnel barriers of the dot. The leakage current from the gates is reduced by minimizing their active area. Further suppression of the leakage is achieved by increasing the etch depth of the channel. The top gates are used to put the dot into the Coulomb blockade regime, and conductance oscillations are observed as the voltage on the side gate is varied.

New Fig. 1, submitted to New Journal of Physics

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Cited by in corpus (16)

• Silicon Quantum Electronics
• Theory of valley-orbit coupling in a Si/SiGe quantum dot
• Charge sensing and controllable tunnel coupling in a Si/SiGe double quantum dot
• Single-electron quantum dot in Si/SiGe with integrated charge-sensing
• Tunable singlet-triplet splitting in a few-electron Si/SiGe quantum dot
• Investigation of Mobility Limiting Mechanisms in Undoped Si/SiGe Heterostructures
• Measurement, control, and decay of quantum-dot spins
• Fast tunnel rates in Si/SiGe one-electron single and double quantum dots
• Pauli spin blockade and lifetime-enhanced transport in a Si/SiGe double quantum dot
• Single-shot measurement and tunnel-rate spectroscopy of a Si/SiGe few-electron quantum dot
• Noise-compensating pulses for electrostatically controlled silicon spin qubits
• Conductance quantization in etched Si/SiGe quantum point contacts
• Si/SiGe quantum dot with superconducting single-electron transistor charge sensor
• Valley splitting in a Si/SiGe quantum point contact
• Sputtered Gold as an Effective Schottky Gate for Strained Si/SiGe Nanostructures
• Coupling a ${}^{73}$Ge nuclear spin to an electrostatically defined quantum dot