Measurement of the Optical Conductivity of Graphene

Kin Fai Mak, Matthew Y. Sfeir, Yang Wu, Chun Hung Lui, James A. Misewich, and Tony F. Heinz
Phys. Rev. Lett. 101, 196405 – Published 7 November 2008

Abstract

Optical reflectivity and transmission measurements over photon energies between 0.2 and 1.2 eV were performed on single-crystal graphene samples on a SiO2 substrate. For photon energies above 0.5 eV, graphene yielded a spectrally flat optical absorbance of (2.3±0.2)%. This result is in agreement with a constant absorbance of πα, or a sheet conductivity of πe2/2h, predicted within a model of noninteracting massless Dirac fermions. This simple result breaks down at lower photon energies, where both spectral and sample-to-sample variations were observed. This “nonuniversal” behavior is explained by including the effects of doping and finite temperature, as well as contributions from intraband transitions.

  • Figure
  • Figure
  • Figure
  • Figure
  • Received 28 June 2008

DOI:https://doi.org/10.1103/PhysRevLett.101.196405

©2008 American Physical Society

Authors & Affiliations

Kin Fai Mak1, Matthew Y. Sfeir2, Yang Wu1, Chun Hung Lui1, James A. Misewich2, and Tony F. Heinz1,*

  • 1Departments of Physics and Electrical Engineering, Columbia University, 538 West 120th Street, New York, New York 10027, USA
  • 2Brookhaven National Laboratory, Upton, New York 11973, USA

  • *Corresponding author: tony.heinz@columbia.edu

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 101, Iss. 19 — 7 November 2008

Reuse & Permissions
Access Options
Collection
Heating up of Superconductors
January 27, 2017

This collection marks the 30th anniversary of the discovery of high-temperature superconductors. The papers selected highlight some of the advances that have been made to date, both in understanding why these compounds behave in the way they do, and in utilizing them in applications. The papers included in the collection have been made free to read.

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×