Fermi-Edge Transmission Resonance in Graphene Driven by a Single Coulomb Impurity

Karnatak, Paritosh and Goswami, Srijit and Kochat, Vidya and Pal, Atindra Nath and Ghosh, Arindam (2014) Fermi-Edge Transmission Resonance in Graphene Driven by a Single Coulomb Impurity. In: PHYSICAL REVIEW LETTERS, 113 (2).

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Abstract

The interaction between the Fermi sea of conduction electrons and a nonadiabatic attractive impurity potential can lead to a power-law divergence in the tunneling probability of charge through the impurity. The resulting effect, known as the Fermi edge singularity (FES), constitutes one of the most fundamental many-body phenomena in quantum solid state physics. Here we report the first observation of FES for Dirac fermions in graphene driven by isolated Coulomb impurities in the conduction channel. In high-mobility graphene devices on hexagonal boron nitride substrates, the FES manifests in abrupt changes in conductance with a large magnitude approximate to e(2)/h at resonance, indicating total many-body screening of a local Coulomb impurity with fluctuating charge occupancy. Furthermore, we exploit the extreme sensitivity of graphene to individual Coulomb impurities and demonstrate a new defect-spectroscopy tool to investigate strongly correlated phases in graphene in the quantum Hall regime.

Item Type:	Journal Article
Publication:	PHYSICAL REVIEW LETTERS
Additional Information:	Copy right for this article belongs to the AMER PHYSICAL SOC, ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	25 Aug 2014 11:52
Last Modified:	25 Aug 2014 11:52
URI:	http://eprints.iisc.ac.in/id/eprint/49663

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