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arXiv · 1802.07331

Strongly enhanced tunneling at total charge neutrality in double bilayer graphene-WSe$_2$ heterostructures

G. William Burg·Nitin Prasad·Kyounghwan Kim·Takashi Taniguchi·Kenji Watanabe·Allan H. MacDonald·Leonard F. Register·Emanuel Tutuc
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Abstract

We report the experimental observation of strongly enhanced tunneling between graphene bilayers through a WSe$_2$ barrier when the graphene bilayers are populated with carriers of opposite polarity and equal density. The enhanced tunneling increases sharply in strength with decreasing temperature, and the tunneling current exhibits a vertical onset as a function of interlayer voltage at a temperature of 1.5 K. The strongly enhanced tunneling at overall neutrality departs markedly from single-particle model calculations that otherwise match the measured tunneling current-voltage characteristics well, and suggests the emergence of a many-body state with condensed interbilayer excitons when electrons and holes of equal densities populate the two layers.

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G. William Burg, Nitin Prasad, Kyounghwan Kim, Takashi Taniguchi, Kenji Watanabe, Allan H. MacDonald, Leonard F. Register, Emanuel Tutuc. 2018-02-20. Strongly enhanced tunneling at total charge neutrality in double bilayer graphene-WSe$_2$ heterostructures. https://doi.org/10.1103/physrevlett.120.177702

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