Effect of Independently Tunable Electron Layer Density on Wigner Crystallization in Electron-Hole Quantum Bilayers

Abstract

A unique evidence of crystalline phase, known as Wigner crystal (WC), is explored in Electron-Hole quantum bilayers (EHBL) by tuning electron layer density independently at zero-temperature and zero-magnetic field. The quantum or dynamical version of Singwi, Tosi, Land and Sjölander (qSTLS) approach is used for obtaining the static density susceptibility. The static density susceptibility plays very important role for exploration of WC phase by showing a divergent behavior at finite wavevector, corresponds to the reciprocal lattice wavevector, during the phase transition from liquid state to WC ground-state. A comparison of present results with a recent results of dependently tunable EHBL system [Phys. Rev. B 66, 205316 (2002)] shows that the onset of Wigner crystallization now occurs at sufficiently lower interlayer spacing by tuning the electron layer density and keeping hole layer density fixed. Further, the prediction of WC phase gets support from the structure factor which exhibits a strong peak near the phase transition point.