arXiv subjects

Tsai-Yu Huang

Publications and source records attributed to Tsai-Yu Huang.

4 recordsLinked to original sources

arXiv2008

From insulator to quantum Hall liquid at low magnetic fields

We have performed low-temperature transport measurements on a GaAs two-dimensional electron system at low magnetic fields. Multiple temperature-independent points and accompanying oscillations are observed in the longitudinal resistivity between the low-field insulator and the quantum Hall (QH) liquid. Our results support the existence of an intermediate regime, where the amplitudes of magneto-oscillations can be well described by conventional Shubnikov-de Haas theory, between the low-field insulator and QH liquid.

cond-mat.mes-hall↗

arXiv2006

Experimental Studies of Low-field Landau Quantization in Two-dimensional Electron Systems in GaAs/AlGaAs Heterostructures

By applying a magnetic field perpendicular to GaAs/AlGaAs two-dimensional electron systems, we study the low-field Landau quantization when the thermal damping is reduced with decreasing the temperature. Magneto-oscillations following Shubnikov-de Haas (SdH) formula are observed even when their amplitudes are so large that the deviation to such a formula is expected. Our experimental results show the importance of the positive magneto-resistance to the extension of SdH formula under the damping induced by the disorder.

cond-mat.mes-hall↗

arXiv2005

On the low-field insulator-quantum Hall conductor transitions

We studied the insulator-quantum Hall conductor transition which separates the low-field insulator from the quantum Hall state of the filling factor $ν=4$ on a gated two-dimensional GaAs electron system containing self-assembled InAs quantum dots. To enter the $ν=4$ quantum Hall state directly from the low-field insulator, the two-dimensional system undergoes a crossover from the low-field localization to Landau quantization. The crossover, in fact, covers a wide range with respect to the magnetic field rather than only a small region near the critical point of the insulator-quantum Hall conductor transition.

cond-mat.mes-hall↗

arXiv2002

Studies of the Temperature-Driven Flow Lines and Phase Transitions in a Two-Dimensional Si/SiGe Hole System

We have performed low-temperature transport experiments on a Si/SiGe hole system. The measured transverse and longitudinal condductivities $σ_{xx}$ and $σ_{xy}$ allow us to study the magnetic-field-induced transitions in the system. In particular, we present the first study of the temperature-driven flow lines in the "anomalous Hall insulator" regime near a Landau level filling factor $ν=1.5$. The "anomalous" temperature-driven flow lines could be due to the unusual energy level scheme in a Si/SiGe hole system. Moreover, for $3<ν<5$, there is a temperature-independent point in $ρ_{xx} (B)$, $ρ_{xy} (B)$, $σ_{xx}$, and $σ_{xy}$ which corresponds to a boundary of the quantum phase transition.

cond-mat.mes-hall↗