  In this study, the electrostatically induced quantum confinement structure,
quantum point contact, has been realized in p-type trilayer tungsten
diselenide-based van der Waals heterostructure with modified van der Waals
contact method with degenerately doped transition metal dichalcogenide
crystals. Clear quantized conductance and pinch-off state through the
one-dimensional confinement were observed by dual-gating of split gate
electrodes and top gate. Conductance plateaus were observed at step of 0.5
$\times$ 2e$^{2}$/h at zero and high magnetic field in addition to quarter
plateaus at a finite bias voltage condition indicating the signature of
spin-polarized quantum point contact realization.
