The low lying excited states in a system of coupled layers of electrons in a gallium arsenide heterostructure are strongly affected by many-body correlations between the electrons for densities as high as rs=5. For a layer spacing of less than 100 nm the function Imχ(q,ω) near q=1.9kF has a large peak at small ω which is apparently a soft-mode precursor to a charge density wave instability. This new peak should be observable with present experimental techniques in realistic samples. The linear gradient of the ‘‘acoustic’’ plasmon is depressed so much by many-body effects that for rs=5 it can become degenerate with the single-particle excitation spectrum for all q.
Excitations of the strongly correlated electron liquid in coupled layers
NEILSON, DAVID;
1993-01-01
Abstract
The low lying excited states in a system of coupled layers of electrons in a gallium arsenide heterostructure are strongly affected by many-body correlations between the electrons for densities as high as rs=5. For a layer spacing of less than 100 nm the function Imχ(q,ω) near q=1.9kF has a large peak at small ω which is apparently a soft-mode precursor to a charge density wave instability. This new peak should be observable with present experimental techniques in realistic samples. The linear gradient of the ‘‘acoustic’’ plasmon is depressed so much by many-body effects that for rs=5 it can become degenerate with the single-particle excitation spectrum for all q.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
