Large Zeeman Splitting in Out-of-Plane Magnetic Field in a Double-Layer Quantum Point Contact

In this study, we observe that the conductance of a quantum point contact on a GaAs/AlGaAs double quantum well depends significantly on the magnetic field perpendicular to the two-dimensional electron gas. In the presence of the magnetic field, the subband edge splitting due to the Zeeman energy reaches 0.09 meV at 0.16 T, thereby suggesting an enhanced g-factor. The estimated g-factor enhancement is 17.5 times that of the bare value. It is considered that a low electron density and high mobility makes it possible to reach a strong many-body interaction regime in which this type of strong enhancement in g-factor can be observed.

Automated summary

The study found that the conductance of a quantum point contact on a GaAs/AlGaAs double quantum well is significantly influenced by the magnetic field in the region, resulting in a 17.5 times enhancement of the g-factor due to Zeeman energy. This phenomenon is mainly attributed to the low electron density and high mobility in the strong many-body interaction region.