Fig. 2: Zero-field quantised conductance via e-QPCs (device D2).
From: Spin polarised quantised transport via one-dimensional nanowire-graphene contacts
a Hole and b electron conductance as a function of bias voltage, VBias, applied between the magnetic electrode and the graphene channel. Each black line represents a bias sweep at a different fixed back gate voltage VBG; the conductance minimum for this e-QPC occurs at 6.6VBG. Blue squares in (a) highlight zero bias hole subbands (h1,2,3). Likewise, purple squares in (b) show zero bias electron subbands, (e1,2), while green triangles highlight finite bias plateaus (e1−,1+). c Conductance vs kF (\({k}_{{{{\rm{F}}}}}=\sqrt{\pi {n}_{{{{\rm{c}}}}}}\)). This data represents a separate measurement, but can be thought of as a trace of the conductance along VBias = 0 in the spectroscopy data. Arrows indicate electron and hole subbands (corresponding to squares in (a, b)). Inset shows a schematic of the 3-terminal measurement configuration. d Spectroscopy data for electron doping (b), plotted as a 2D map of transconductance against VBias and VBG. Plateaus occur where dG/dV = 0, which is represented in white. Black boxes represent the area fit with a 2D Lorentzian function, to find the local minima and quantify the position of the finite bias plateaus (e1+,1−).
