Measurement Back-Action in Stacked Graphene Quantum Dots.
We present an electronic transport experiment in graphene where both classical and quantum mechanical charge detector back-action on a quantum dot are investigated. The device consists of two stacked graphene quantum dots separated by a thin layer of boron nitride. This device is fabricated by van der Waals stacking and is equipped with separate source and drain contacts to both dots. By applying a finite bias to one quantum dot, a current is induced in the other unbiased dot. We present an explanation of the observed measurement-induced current based on strong capacitive coupling and energy dependent tunneling barriers, breaking the spatial symmetry in the unbiased system. This is a special feature of graphene-based quantum devices. The experimental observation of transport in classically forbidden regimes is understood by considering higher-order quantum mechanical back-action mechanisms.
Solid State Physics Laboratory and ‡Institute for Theoretical Physics, ETH Zurich , 8093 Zurich, Switzerland.
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D
Bischoff
Solid State Physics Laboratory and ‡Institute for Theoretical Physics, ETH Zurich , 8093 Zurich, Switzerland.
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M
Eich
Solid State Physics Laboratory and ‡Institute for Theoretical Physics, ETH Zurich , 8093 Zurich, Switzerland.
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O
Zilberberg
Solid State Physics Laboratory and ‡Institute for Theoretical Physics, ETH Zurich , 8093 Zurich, Switzerland.
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C
Rössler
Solid State Physics Laboratory and ‡Institute for Theoretical Physics, ETH Zurich , 8093 Zurich, Switzerland.
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T
Ihn
Solid State Physics Laboratory and ‡Institute for Theoretical Physics, ETH Zurich , 8093 Zurich, Switzerland.
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K
Ensslin
Graphene nanoribbon; capacitively coupled double dot; charge detection; measurement back-action; van der Waals heterostructure