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arXiv · 1907.08523

Tunable coupling and isolation of single electrons in silicon metal-oxide-semiconductor quantum dots

H. G. J. Eenink·L. Petit·W. I. L. Lawrie·J. S. Clarke·L. M. K. Vandersypen·M. Veldhorst
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Abstract

Extremely long coherence times, excellent single-qubit gate fidelities and two-qubit logic have been demonstrated with silicon metal-oxide-semiconductor spin qubits, making it one of the leading platforms for quantum information processing. Despite this, a long-standing challenge in this system has been the demonstration of tunable tunnel coupling between single electrons. Here we overcome this hurdle with gate-defined quantum dots and show couplings that can be tuned on and off for quantum operations. We use charge sensing to discriminate between the (2,0) and (1,1) charge states of a double quantum dot and show excellent charge sensitivity. We demonstrate tunable coupling up to 13 GHz, obtained by fitting charge polarization lines, and tunable tunnel rates down to below 1 Hz, deduced from the random telegraph signal. The demonstration of tunable coupling between single electrons in a silicon metal-oxide-semiconductor device provides significant scope for high-fidelity two-qubit logic toward quantum information processing with standard manufacturing.

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H. G. J. Eenink, L. Petit, W. I. L. Lawrie, J. S. Clarke, L. M. K. Vandersypen, M. Veldhorst. 2019-07-19. Tunable coupling and isolation of single electrons in silicon metal-oxide-semiconductor quantum dots. https://doi.org/10.1021/acs.nanolett.9b03254

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