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arXiv · 1807.11064

Lifting of Spin Blockade by Charged Impurities in Si-MOS Double Quantum Dot Devices

Evelyn King·Joshua S. Schoenfield·M. J. Calderón·Belita Koiller·André Saraiva·Xuedong Hu·HongWen Jiang·Mark Friesen·S. N. Coppersmith
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Abstract

One obstacle that has slowed the development of electrically gated metal-oxide-semiconductor (MOS) singlet-triplet qubits is the frequent lack of observed spin blockade, even in samples with large singlet-triplet energy splittings. We present theoretical and experimental evidence that the cause of this problem in MOS double quantum dots is the stray positive charges in the oxide inducing accidental levels near the device's active region that allow spin blockade lifting. We also present evidence that these effects can be mitigated by device design modifications, such as overlapping gates.

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Evelyn King, Joshua S. Schoenfield, M. J. Calderón, Belita Koiller, André Saraiva, Xuedong Hu, HongWen Jiang, Mark Friesen, S. N. Coppersmith. 2018-07-29. Lifting of Spin Blockade by Charged Impurities in Si-MOS Double Quantum Dot Devices. https://doi.org/10.1103/physrevb.101.155411

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