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Title: Correlation effects in the capacitance of a gated carbon nanotube

Abstract

For a capacitor made of a semiconducting carbon nanotube (CNT) suspended above a metallic gate, Coulomb correlations between individual electrons can lead to a capacitance that is much larger than the geometric capacitance. We argue that when the average spacing n-1 between electrons within the low density 1-dimensional electron gas (1DEG) in the CNT is larger than the physical separation d between the CNT and the gate, the enhancement of capacitance is expected to be big. A recent experiment,1 however, has observed no obvious increase of capacitance even at very low electron density. We show that this smaller capacitance can be understood as the result of the confining potential produced by the potential difference between the source/drain electrodes and the gate, which compresses the 1DEG when the electron number decreases. We suggest that by profiling the potential with the help of multiple split gates, one can return to the case of a uniform 1DEG with anomalously large capacitance.

Authors:
; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division; National Science Foundation (NSF)
OSTI Identifier:
1392102
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 91; Journal Issue: 15
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Fu, Han, Shklovskii, B. I., and Skinner, Brian. Correlation effects in the capacitance of a gated carbon nanotube. United States: N. p., 2015. Web. doi:10.1103/PhysRevB.91.155118.
Fu, Han, Shklovskii, B. I., & Skinner, Brian. Correlation effects in the capacitance of a gated carbon nanotube. United States. doi:10.1103/PhysRevB.91.155118.
Fu, Han, Shklovskii, B. I., and Skinner, Brian. Wed . "Correlation effects in the capacitance of a gated carbon nanotube". United States. doi:10.1103/PhysRevB.91.155118.
@article{osti_1392102,
title = {Correlation effects in the capacitance of a gated carbon nanotube},
author = {Fu, Han and Shklovskii, B. I. and Skinner, Brian},
abstractNote = {For a capacitor made of a semiconducting carbon nanotube (CNT) suspended above a metallic gate, Coulomb correlations between individual electrons can lead to a capacitance that is much larger than the geometric capacitance. We argue that when the average spacing n-1 between electrons within the low density 1-dimensional electron gas (1DEG) in the CNT is larger than the physical separation d between the CNT and the gate, the enhancement of capacitance is expected to be big. A recent experiment,1 however, has observed no obvious increase of capacitance even at very low electron density. We show that this smaller capacitance can be understood as the result of the confining potential produced by the potential difference between the source/drain electrodes and the gate, which compresses the 1DEG when the electron number decreases. We suggest that by profiling the potential with the help of multiple split gates, one can return to the case of a uniform 1DEG with anomalously large capacitance.},
doi = {10.1103/PhysRevB.91.155118},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 15,
volume = 91,
place = {United States},
year = {Wed Apr 01 00:00:00 EDT 2015},
month = {Wed Apr 01 00:00:00 EDT 2015}
}