id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
ap-1396	Jones, H. F.	Perturbation Theory for PT-Symmetric Sinusoidal Optical Lattices at the Symmetry-Breaking Threshold	2011	5	.pdf	application/pdf	3057	146	71	2 Band structure at threshold At the threshold λ = 1, the potential V in Eq. (2) be- comes the complex exponential V = V0 exp(2iπx/a), for which the Schrödinger equation is − ψ′′ − V0 exp(2iπx/a)ψ = βψ. 2: Characteristic behaviour of error functions whose arguments are (a) real or (b) have a large imaginary part.	cache/ap-1396.pdf	txt/ap-1396.txt