A room-temperature gate-tunable bipolar valley Hall effect in molybdenum disulfide/tungsten diselenide heterostructures

Room-temperature quantum Hall effect in graphene.

The quantum Hall effect (QHE), one example of a quantum phenomenon that occurs on a truly macroscopic scale, has attracted intense interest since its discovery in 1980 and has helped elucidate many important aspects of quantum physics. It has also led to the establishment of a new metrological standard, the resistance quantum. Disappointingly, however, the QHE has been observed only at liquid-h...

Electrical gate control of spin current in van der Waals heterostructures at room temperature

Two-dimensional (2D) crystals offer a unique platform due to their remarkable and contrasting spintronic properties, such as weak spin-orbit coupling (SOC) in graphene and strong SOC in molybdenum disulfide (MoS2). Here we combine graphene and MoS2 in a van der Waals heterostructure (vdWh) to demonstrate the electric gate control of the spin current and spin lifetime at room temperature. By per...

Gate-tunable resonant tunneling in double bilayer graphene heterostructures.

We demonstrate gate-tunable resonant tunneling and negative differential resistance in the interlayer current-voltage characteristics of rotationally aligned double bilayer graphene heterostructures separated by hexagonal boron nitride (hBN) dielectric. An analysis of the heterostructure band alignment using individual layer densities, along with experimentally determined layer chemical potenti...

Tunable Valley Polarization and Valley Orbital Magnetic Moment Hall Effect in Honeycomb Systems with Broken Inversion Symmetry

In this Letter, a tunable valley polarization is investigated for honeycomb systems with broken inversion symmetry such as transition-metal dichalcogenide MX2 (M = Mo, W; X = S, Se) monolayers through elliptical pumping. Compared to circular pumping, elliptical pumping is a more universal and effective method to create coherent valley polarization. When two valleys of MX2 monolayers are doped o...

The Valley Hall Effect in MoS2 Transistors