Electron Liquids in Coupled Quantum Wells

• Authors: L. Świerkowski , J. Szymański , D. Neilson
• Languages of publication: EN

Abstracts

EN

A system comprising of two adjacent layers of conduction electrons or alternatively a layer of electrons and a layer of holes can exhibit novel instabilities in the liquid phase towards inhomogeneous ground states. The carriers in the two layers can couple to each other through the Coulomb interaction but they are not permitted to tunnel so that the charges in one layer act as a polarisable background for the other layer. The presence of a second layer encourages the formation of novel ground states with inhomogeneous density distributions. We find theoretical evidence for the existence of charge density wave ground states and also a coupled Wigner crystal. These exist at much higher densities than the Wigner crystallisation density for the single layer case. The existence of these inhomogeneous ground states leads to significant modifications of the low lying excitation spectrum in the uniform liquid phase. Near the transitions to both the charge density wave and the coupled Wigner crystal phases we find evidence of the development in the liquid phase of new soft mode excitations of finite wave number q that are precursors of the inhomogeneous ground states. Near the transition to the coupled Wigner crystal we observe a strong tendency of the single particle excitation spectrum for the liquid phase to renormalise into a single line that has a dispersion closely resembling the phonon dispersion curve for the solid.

Keywords

EN

73.40.Lq; 71.45.Gm; 71.45.Lr

Discipline

• 71.45.Lr: Charge-density-wave systems(see also 75.30.Fv Spin-density waves)
• 71.45.Gm: Exchange, correlation, dielectric and magnetic response functions, plasmons
• 73.40.Lq: Other semiconductor-to-semiconductor contacts,p-njunctions, and heterojunctions

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 1993
• Volume: 84
• Issue: 3
• Pages: 445-457

Dates

published

1993-09

Contributors

author

L. Świerkowski

• School of Physics, University of New South Wales, Kensington 2033, Australia

author

J. Szymański

• Telecom Research Laboratories, 770 Blackburn Road, Clayton Vic. 3168, Australia

author

D. Neilson

• School of Physics, University of New South Wales, Kensington 2033, Australia

Identifiers

DOI

10.12693/APhysPolA.84.445