ORIGINAL PAPER Electron acoustic dressed soliton in quantum plasma P Chatterjee 2 *, G Mondal 3 and C S Wong 1 1 Plasma Research Laboratory, Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia 2 Department of Mathematics, Siksha Bhavana, Visva-Bharati University, Santiniketan 731235, West Bengal, India 3 Department of Mathematics, Siksha Satra, Visva-Bharati University, Sriniketan 731236, West Bengal, India Received: 11 January 2013 / Accepted: 10 April 2013 / Published online: 9 May 2013 Abstract: The nonlinear propagation of electron-acoustic waves in three components unmagnetized dense quantum plasma consisting of inertially cold electrons, inertia-less hot electrons and immobile ions is investigated using a one dimensional quantum hydrodynamic model. Using the standard reductive perturbation technique the Korteweg–de Vries equation is derived. The higher order inhomogeneous differential equation is obtained for the dressed soliton. The dynamical equation for dressed soliton is solved using renormalization method and the particular solution is obtained by using the method developed by Chatterjee et al. (Phys Plasmas 16:072102, 2009). Keywords: Quantum plasma; Quantum hydrodynamic model; Dressed soliton PACS Nos.: 52.35.Sb; 52.35.Mw; 52.35.-g; 52.65.Vv 1. Introduction Wave propagation and instabilities in quantum plasma are one of the rapidly growing areas of plasma science as there are examples in high density plasmas where quantum effects on plasmas are no more negligible. Mainly two mathematical formulations, Wigner-Poisson and the Schro ¨dinger-Poisson distribution have been used and have been widely discussed by Manfredi [1]. Nonlinear struc- tures like solitons, shocks and vortices in quantum plasmas have been investigated by several authors [2–5]. To study ion acoustic solitary waves (IASWs) in quantum plasma, one dimensional quantum hydrodynamic model (QHD) has been used by several authors. Andreev [6] and Garcia et al. [7] have studied nonlinear coupling between high and low frequency motions in quantum plasma. Propagation of solitons in quantum plasma has also been studied using nonperturbative approach [8–10]. Electron acoustic waves (EAWs) are high-frequency dispersive plasma waves, where a small number of inertial cold electrons oscillate against dominant thermalized iner- tia-less hot electrons, providing the necessary restoring force. These EAWs play an important role in laboratory as well as in space plasmas. As the two-electron populations (one hot and one cold) occur frequently in fusion devices and in the auroral ionosphere [11, 12], EAWs can exist in such a two-electron temperature plasma. It can also explain the electrostatic component of the broadband electrostatic noise (BEN) observed in magnetosphere [13–15] and in the geo- magnetic tail [16, 17]. Two-electron temperature plasmas also appear in the Earth’s bow shock, the heliospheric ter- mination shock and in planetary and neutron star magneto- spheres. The linear and nonlinear properties of EAWs in unmagnetized plasmas have been investigated by many authors [18, 19]. Electron-acoustic (EA) solitary waves (EASWs) have also been studied by several authors [20–22]. Dubouloz et al. [18] have studied EASWs solitons in one-dimensional, unmagnetized, collisionless plasma. Mace et al. [19] have investigated the effect of finite ion temperature on EASWs in an unmagnetized plasma. They have shown the existence of a negative potential soliton associated with a compression of the cold electron density. Large amplitude solitary waves have also been studied using Sagdeev’s pseudopotential technique. Chatterjee and Roychoudhury [20] have studied large amplitude EASWs in plasmas and Sahu and Roychoudhury [21] have exten- ded their study in relativistic plasmas with nonthermal electrons. *Corresponding author, E-mail: prasantachatterjee1@rediffmail.com Indian J Phys (August 2013) 87(8):827–834 DOI 10.1007/s12648-013-0292-6 Ó 2013 IACS