Other applications
Chen et al.,PRB 54, 12798 (1996)
Nelson and Shnerb, PRE 58, 1383 (1998)
Mudry et al. PRL 80, 4257 (1998)
Bender and Boettcher, PRL 80, 5243 (1998)
complex spectrum _ PT symmetry breaking
Lehrer and Nelson, cond-mat/9806016
Boson crystal and delocalization