Thursday, July 21, 2016

Abstract-Terahertz Spectroscopy of Individual Single-Walled Carbon Nanotubes as a Probe of Luttinger Liquid Physics

 Department of Applied Physics, Yale University, New Haven, Connecticut 06511, United States
 Department of Physics, University of North Florida, Jacksonville, Florida 32224, United States
Nano Lett., Article ASAP
DOI: 10.1021/acs.nanolett.6b01485
Publication Date (Web): July 20, 2016
Copyright © 2016 American Chemical Society

Luttinger liquid theory predicts that collective electron excitations due to strong electron–electron interactions in a one-dimensional (1D) system will result in a modification of the collective charge-propagation velocity. By utilizing a circuit model for an individual metallic single-walled carbon nanotube as a nanotransmission line, it has been shown that the frequency-dependent terahertz impedance of a carbon nanotube can probe this expected 1D Luttinger liquid behavior. We excite terahertz standing-wave resonances on individual antenna-coupled metallic single-walled carbon nanotubes. The terahertz signal is rectified using the nanotube contact nonlinearity, allowing for a low-frequency readout of the coupled terahertz current. The charge velocity on the nanotube is determined from the terahertz spectral response. Our measurements show that a carbon nanotube can behave as a Luttinger liquid system with charge-propagation velocities that are faster than the Fermi velocity. Understanding what determines the charge velocity in low-dimensional conductors is important for the development of next generation nanodevices.

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