Voltage controlled exchange energies of a two electron silicon double quantum dot with and without charge defects in the dielectric

Abstract

Quantum dots are artificial atoms used for a multitude of purposes. Charge defects are commonly present and can significantly perturb the designed energy spectrum and purpose of the dots. Voltage controlled exchange energy in silicon double quantum dots (DQD) represents a system that is very sensitive to charge position and is of interest for quantum computing. We calculate the energy spectrum of the silicon double quantum dot system using a full configuration interaction that uses tight binding single particle wavefunctions. This approach allows us to analyze atomic scale charge perturbations of the DQD while accounting for the details of the complex momentum space physics of silicon (i.e., valley and valley-orbit physics). We analyze how the energy levels and exchange curves for a DQD are affected by nearby charge defects at various positions relative to the dot, which are consistent with defects expected in the metal-oxide-semiconductor system.

5 pages, 3 figures

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Cited by in corpus (10)

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• Exchange coupling in a linear chain of three quantum-dot spin qubits in silicon
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• Noise-compensating pulses for electrostatically controlled silicon spin qubits
• Valley Phase and Voltage Control of Coherent Manipulation in Si Quantum Dots
• High-precision real-space simulation of electrostatically-confined few-electron states
• Calculation of tunnel-couplings in open gate-defined disordered quantum dot systems
• Path integral simulation of exchange interactions in CMOS spin qubits
• Transport spectroscopy of low disorder silicon tunnel barriers with and without Sb implants