We can see from Figure 6 that both methods give the same results

We can see from Figure 6 that both methods give the same results at low T for V g = −0.165 V, implying that buy Selonsertib the influence of background MR is diminished as the amount of short-range scattering potential is increased. In what follows, we will focus on the issue about direct I-QH transitions. Huckestein has suggested that the direct I-QH transition can be identified as a crossover from weak localization to the onset of Landau quantization, resulting in a strong reduction of the conductivity. The field B ~ 1/μ separates these two regions which are characterized by opposite T dependences and are characterized by ρ xx ~ ρ xy. In his argument, μ is taken to be the transport mobility. Nevertheless,

recent experimental results [11–13] demonstrate that different mobilities should be introduced to understand transport near a direct I-QH transition; the observed direct I-QH transition can be irrelevant to Landau quantization, while Landau quantization does not always cause the formation of QH states. Furthermore, it has already been demonstrated in various kinds of 2DES that the crossing point ρ xx = ρ xy can occur TEW-7197 clinical trial before or after the appearance of the T-independent point that corresponds to a

direct I-QH transition. https://www.selleckchem.com/products/pha-848125.html Moreover, the strongly T-dependent Hall slope induced by e-e interactions may affect the position of ρ xx = ρ xy at different T. As shown in Figure 2b for V g = −0.145 V, the direct I-QH transition characterized by an approximately T-independent

crossing point B c in ρ xx does occur at the field where ρ xx ~ ρ xy even though ρ xy slightly depends on T. In addition, the inverse of the estimated Drude mobility 1/μ D ~ 0.26 T is found to be close to B c. To this extent, Huckestein’s model seems to be reasonable. However, find more we can see that there are no apparent oscillations in ρ xx around B c and that the onset of strong localization occurs at B > 1.37 T, as characterized by a well-quantized ν = 2 Hall plateau and vanishing ρ xx with increasing B, more than five times larger than B c. In order to test the validity of the relation ρ xx ~ ρ xy at B c, different gate voltages were applied to vary the effective amount of disorder and carrier density in the 2DES. As shown in Figure 2a, by increasing V g to −0.125 V, ρ xx becomes smaller than ρ xy at B c ~ 0.26 T, while ρ xx ~ ρ xy at a smaller field of approximately 0.21 T, which is shown to be close to 1/μ D ~ 0.22 T rather than B c. Moreover, by decreasing V g to −0.165 V, ρ xx ~ ρ xy appears at B ~ 0.33 T which is larger than B c ~ 0.29 T, as shown in Figure 2c. The inverse Drude mobility 1/μ D ~ 0.35 is also found to be close to the field where ρ xx ~ ρ xy under this gate voltage. In all three cases, the crossings of σ xx and σ xy coincide with those of ρ xx and ρ xy, as shown in Figure 2 for each V g.

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