Measuring cotunneling in its wake

Zilberberg, Oded and Carmi, Assaf and Romito, Alessandro (2014) Measuring cotunneling in its wake. Physical review B, 90 (20): 205413. ISSN 2469-9950

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1403.5897v3 - Accepted Version
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Abstract

We introduce a rate formalism to treat classically forbidden electron transport through a quantum dot (cotunneling) in the presence of a coupled measurement device. We demonstrate this formalism for a toy model case of cotunneling through a single-level dot while being coupled to a strongly pinched-off quantum point contact (QPC). We find that the detector generates three types of back-action: the measurement collapses the coherent transport through the virtual state, but at the same time allows for QPC-assisted incoherent transport, and widens the dot level. Last, we obtain the measured cotunneling time from the cross correlation between dot and QPC currents.