Eur. Phys. J. B 71, 121-124 (2009)
https://doi.org/10.1140/epjb/e2009-00265-5

Nonlinear delocalization on disordered Stark ladder

¹ Universié de Toulouse, UPS, Laboratoire de Physique Théorique (IRSAMC), 31062 Toulouse, France
² CNRS, LPT (IRSAMC), 31062 Toulouse, France
³ Departamento de Física, Lab. TANDAR, Comisión Nacional de Energía Atómica, Av. del Libertador 8250, 1429 Buenos Aires, Argentina

Received: 24 April 2009
Revised: 29 June 2009
Published online: 24 July 2009

Abstract

We study effects of weak nonlinearity on localization of waves in disordered Stark ladder corresponding to propagation in presence of disorder and a static field. Our numerical results show that nonlinearity leads to delocalization with subdiffusive spreading along the ladder. The exponent of spreading remains close to its value in absence of the static field. The delocalization implies the existence of statistical entanglement between far away parts of the spreading wave packet indicating importance of long-range effects.