Constants (graphene._constants)

Physical constants common in the study of graphene. These constants are not found in scipy.constants.

Carbon

Variable	Constant	Value	Unit	Ref
m_C	Mass of Carbon atom	1.9926468799199998e-26	kg	[1]

Geometry

Variable	Constant	Value	Unit	Ref
thickness	Thickness of a single layer of graphene	3.4e-10	m
a	Interatom spacing on a graphene lattice	1.46e-10	m
A	Area of a unit cell of graphene lattice \(A=3\sqrt{3}a^2/2\)	5.24e-20	m 2	[2]

Tight-Binding Parameters

Variable	Constant	Value	Unit
g0	Interatom hopping potential \(\gamma_0\)	4.49e-19	J
g0prime	Particle hole asymmetry \(\gamma_0'\)	0	J
vF	Fermi velocity \(v_F=3\gamma_0a/2\)	9.07e5	m/s

Electromagnetic / Optical

Variable	Constant	Value	Units	Ref
W	Work Function	7.37e-19	J
sigma_0	Intrinsic Conductivity \(\sigma_0=e^2/4\hbar\)	6.085337014469867e-05	S-m
abs0	Intrinsic absorption \(\pi\alpha\)	0.022925309222367483	none	[3]

References

[1] J. Emsley, The Elements, Oxford Chemistry Guides (Oxford Univ. Press, New York, NY, 1995).

[2] Castro Neto, A.H., Guinea, F., Peres, N.M.R., Novoselov, K.S., and Geim, A.K. (2009). The electronic properties of graphene. Rev. Mod. Phys. 81, 109–162. https://link.aps.org/doi/10.1103/RevModPhys.81.109.

[3] Nair, R.R., Blake, P., Grigorenko, A.N., Novoselov, K.S., Booth, T.J., Stauber, T., Peres, N.M.R., and Geim, A.K. (2008). Fine Structure Constant Defines Visual Transparency of Graphene. Science 320, 1308–1308. http://www.sciencemag.org/cgi/doi/10.1126/science.1156965