Experimental evidence for a two-dimensional quantized Hall insulator

Stable two-dimensional dumbbell stanene: A quantum spin Hall insulator

Peizhe Tang,1,2 Pengcheng Chen,1 Wendong Cao,1 Huaqing Huang,1 Seymur Cahangirov,2 Lede Xian,2 Yong Xu,3,4 Shou-Cheng Zhang,3,4 Wenhui Duan,1,4,5,* and Angel Rubio2,† 1State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China 2Nano-Bio Spectroscopy Group, Departamento Fı́sica de Materiales, Universidad del Paı́s Vasco, Centro de Fı́s...

Experimental evidence for direct insulator-quantum Hall transition in multi-layer graphene

We have performed magnetotransport measurements on a multi-layer graphene flake. At the crossing magnetic field Bc, an approximately temperature-independent point in the measured longitudinal resistivity ρxx, which is ascribed to the direct insulator-quantum Hall (I-QH) transition, is observed. By analyzing the amplitudes of the magnetoresistivity oscillations, we are able to measure the quantu...

Tunable insulator-quantum Hall transition in a weakly interacting two-dimensional electron system

We have performed low-temperature measurements on a gated two-dimensional electron system in which electron-electron (e-e) interactions are insignificant. At low magnetic fields, disorder-driven movement of the crossing of longitudinal and Hall resistivities (ρxx and ρxy) can be observed. Interestingly, by applying different gate voltages, we demonstrate that such a crossing at ρxx ~ ρxy can oc...

Topological insulator: a new quantized spin Hall resistance robust to dephasing.

The dephasing effect on the quantum spin Hall effect (QSHE) is studied. Without dephasing, the longitudinal resistance in a QSHE system exhibits the quantum plateaus. We find that these quantum plateaus are robust against the normal dephasing but fragile with the spin dephasing. Thus, these quantum plateaus survive only in mesoscopic samples. Moreover, the longitudinal resistance increases line...

The Quantized Hall Effect