Transport characteristics of InSb trench-type in-plane gate quantum point contact

An InSb quantum point contact (QPC) has been fabricated in a two-dimensional InSb heterostructure by using a trench-type in-plane gate. The magneto-transport characteristics show magneto-depopulation of 1D subbands under a perpendicular magnetic field and crossings of the 1D subbands under an in-plane magnetic field. The estimated effective g-factor has in-plane (|g*x| ∼ |g*y| ∼ 40) and out-of-plane (|g*z| ∼ 60) anisotropy. When a positive voltage is applied to the trench gate, the QPC device shows the typical characteristics of parallel channels, suggesting electron accumulation along the side walls of the trench.