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Valley blockade in a silicon double quantum dot



Justin K. Perron, Michael Gullans, Jacob Taylor, Michael Stewart, Neil M. Zimmerman


Electrical transport in double quantum dots (DQD) is useful for illuminating many interesting aspects of the carrier states in quantum dots. Here we show data comparing bias triangles (i.e., regions of allowed current in DQDs) at positive and negative bias voltage, and, in particular, a systematic asymmetry in the size of the bias triangles at the two bias polarities; this asymmetry is commonly associated with Pauli Spin Blockade (PSB). However, the qualitative features of the asymmetry in our data, including i) lack of odd/even filling, ii) same polarity of asymmetry across many charge transitions, iii) lack of systematic dependence on magnetic field, and iv) strong dependence on a gate voltages, are all in disagreement with the predictions of standard PSB. In contrast, we introduce a model based on selective filling of valley states in the DQD that predicts all of the qualitative features in our data.
Physical Review Letters


Si, valley physics


Perron, J. , Gullans, M. , Taylor, J. , Stewart, M. and Zimmerman, N. (2017), Valley blockade in a silicon double quantum dot, Physical Review Letters, [online],, (Accessed May 22, 2024)


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Created November 12, 2017, Updated October 12, 2021