Quantum Hall resistance standards from graphene grown by chemical vapour deposition on silicon carbide

Abstract

Replacing GaAs by graphene to realize more practical quantum Hall resistance standards (QHRS), accurate to within 10−9 in relative value, but operating at lower magnetic fields than 10 T, is an ongoing goal in metrology. To date, the required accuracy has been reported, only few times, in graphene grown on SiC by Si sublimation, under higher magnetic fields. Here, we report on a graphene device grown by chemical vapour deposition on SiC, which demonstrates such accuracies of the Hall resistance from 10 T up to 19 T at 1.4 K. This is explained by a quantum Hall effect with low dissipation, resulting from strongly localized bulk states at the magnetic length scale, over a wide magnetic field range. Our results show that graphene-based QHRS can replace their GaAs counterparts by operating in as-convenient cryomagnetic conditions, but over an extended magnetic field range. They rely on a promising hybrid and scalable growth method and a fabrication process achieving low-electron-density devices.

Magnetic field driven ambipolar quantum Hall effect in epitaxial graphene close to the charge neutrality point

“…The quantum Hall plateaus observed in graphene on SiC (G/SiC) have a high breakdown current [4] and appear at lower magnetic fields [5] with respect to graphene deposited on SiO 2 [6]. The quantum plateaus in G/SiC devices are much larger in magnetic field than those obtained in graphene encapsulated in hBN [7], because they are stabilized by charge transfer [8] and disorder [9]. Thanks to these properties, it was recently demonstrated that G/SiC can act as a quantum electrical resistance standard [10], even in experimental conditions relaxed with respect to the state of the art in GaAs-based quantum wells [11].…”

Combining graphene with silicon carbide: synthesis and properties – a review

“…The most widely studied among the carbon sources is propane [114,121,124,126,[128][129][130][131][132][133][134][135][136][137]. There is only a few works devoted to ethene [125], toluene [127] and xylene [127] as carbon sources for graphene growth on silicon carbide.…”

“…There is a lot of excellent reports in literature dealing with deposition of graphene from external sources on metallic surfaces (Cu, Ni, Ir, etc) and on dielectric wafers (SiC, sapphire, Si, etc.). Following the main purpose of this review paper, we focus only on the CVD and MBE growth of graphene on silicon carbide [114,121,[123][124][125][126][127][128][129][130][131][132][133][134][135][136][137][138][139][140][141]. Therefore, the aim of this subsection is twofold: (i) to understand the main difference between thermal decomposition of silicon carbide and bottom-up growth of graphene on SiC and (ii) to extensively review the literature concerning the CVD and MBE growth processes with participation of SiC substrate.…”

Nonlinear transport of graphene in the quantum Hall regime

“…Various works have proved the universality and reproducibility of quantum Hall resistance standard metrology in graphene with accuracy as high as part-per-billion [20][21][22][23][24]. Quantum resistance devices based on graphene have been realized on graphene grown on silicon carbide wafer [20][21][22][23][24][25][26]. More importantly, QH effect can be realized in graphene at room temperature [27], which makes graphene-based QH device a very attractive choice of a practical resistance definition for routine calibration, and a potential alternative to replace GaAs based device in the SI unit definition.…”

“…Therefore, the metrology of resistance standard, including a practical (non-SI) definition for increasing potential end users, is getting more and more important. Various works have proved the universality and reproducibility of quantum Hall resistance standard metrology in graphene with accuracy as high as part-per-billion [20][21][22][23][24]. Quantum resistance devices based on graphene have been realized on graphene grown on silicon carbide wafer [20][21][22][23][24][25][26].…”