TRANSVERSE PSEUDOSPIN SUSCEPTIBILITY AND TUNNELING PARAMETERS OF DOUBLE-LAYER ELECTRON-GAS SYSTEMS

The subbands of weakly coupled double-layer two-dimensional-electron-g as systems consist of narrowly spaced pairs whose corresponding wave f unctions are symmetric and antisymmetric combinations of isolated laye r subband wave functions. The energetic spacing within a pair is 2t, w here t is the interlayer tunneling amplitude. t is an important parame ter in modeling these systems and, if interactions could be neglected, it would be proportional to beating frequencies seen in weak-field ma gnetic oscillations experiments and therefore readily measurable. We p oint out that interactions alter the beating frequency. We discuss sim ilarities and differences between this effect and exchange-correlation -enhanced spin splitting.