We study the behavior of 1D systems in GaAs/AlGaAs hetero¬structures, whose filling is controlled by field effect. The confining poten¬tial is defined by fork-shaped interdigital metallic gates having lithogra-phic width ~150 nm. Measurement of the sample differential capa¬citance enable us to control the filling of single 1D subbands and investigate the thermodynamic and the tunneling DOS. The development of a structure related to spin splitting is studied as a function of both magnetic field and confinement. At the lowest 1D confinements, we find an enhanced g-fac¬tor g?15, which is a factor 35 larger than the "bare" value g=-0.44 for con¬duction band electrons in bulk GaAs. With increasing confinement, the g-factor is progressively suppressed. The observations are explained by theoretical models in terms of competition between exchange interactions and kinetic energy of edge electrons.
Study of spin-splitting in one-dimensional systems by magneto-capacitance measurements
IPallecchi;
2002
Abstract
We study the behavior of 1D systems in GaAs/AlGaAs hetero¬structures, whose filling is controlled by field effect. The confining poten¬tial is defined by fork-shaped interdigital metallic gates having lithogra-phic width ~150 nm. Measurement of the sample differential capa¬citance enable us to control the filling of single 1D subbands and investigate the thermodynamic and the tunneling DOS. The development of a structure related to spin splitting is studied as a function of both magnetic field and confinement. At the lowest 1D confinements, we find an enhanced g-fac¬tor g?15, which is a factor 35 larger than the "bare" value g=-0.44 for con¬duction band electrons in bulk GaAs. With increasing confinement, the g-factor is progressively suppressed. The observations are explained by theoretical models in terms of competition between exchange interactions and kinetic energy of edge electrons.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
