相关论文: Evidence for Helical Edge Modes in Inverted InAs/G…

We have studied experimentally the low temperature conductivity of mesoscopic size InAs/GaSb quantum well Hall bar devices in the inverted regime. Using a pair of electrostatic gates we were able to move the Fermi level into the…

Inverted-gap GaSb/InAs quantum wells have long been predicted to show quantum spin Hall insulator (QSHI) behavior. The experimental characterization of the QSHI phase in these systems has relied on the presence of quantized edge transport…

We report low-temperature transport measurements in strained InAs/Ga0.68In0.32Sb quantum wells, which supports time-reversal symmetry-protected helical edge states. The temperature and bias voltage dependence of the helical edge conductance…

We present an experimental study of inverted InAs/GaSb composite quantum wells in the hybridization regime and contacted by superconducting electrodes. A front gate is used to vary the Fermi level into the mini-gap, where recent experiments…

Transport measurements are performed on InAs/GaSb double quantum wells at zero and finite magnetic fields applied parallel and perpendicular to the quantum wells. We investigate a sample in the inverted regime where electrons and holes…

Mainstream among topological insulators, GaSb/InAs quantum wells present a broken gap alignment for the energy bands which supports the quantum spin Hall insulator phase and forms an important building block in the search of exotic states…

We have investigated low-temperature electronic transport on InAs/GaSb double quantum wells, a system which promises to be electrically tunable from a normal to a topological insulator. Hall bars of $50\,\mu$m in length down to a few $\mu$m…

We investigate low-temperature transport through single InAs quantum wells and broken-gap InAs/GaSb double quantum wells. Non-local measurements in the regime beyond bulk pinch-off confirm the presence of edge conduction in InAs quantum…

We present transport and scanning SQUID measurements on InAs/GaSb double quantum wells, a system predicted to be a two-dimensional topological insulator. Top and back gates allow independent control of density and band offset, allowing…

The experiments in quantum spin Hall insulator candidate materials, such as HgTe/CdTe and InAs/GaSb heterostructures, indicate that in addition to the topologically protected helical edge modes these multilayer heterostructures may also…

InAs/GaSb heterostructure is one of the systems where quantum spin Hall effect is predicted to arise. However, as confirmed by recent experimental studies, the most significant highlight of the effect i.e., the conductance quantization due…

We investigate lateral p-n junctions, electrostatically defined in 14 nm-wide HgTe-based quantum wells (QWs) with inverted band structure. The p-n junctions resistances are close to $h/2e^2$, consistent with some previous experiments on…

We observe the magnetic oscillation of electric conductance in the two-dimensional InAs/GaSb quantum spin Hall insulator. Its insulating bulk origin is unambiguously demonstrated by the antiphase oscillations of the conductance and the…

We present a multi-probe transport analysis that effectively separates bulk and edge currents in large Hall bar devices with standard geometries. Applied to transport measurements on all possible four-probe configurations of six-probe Hall…

We report on the observation of a helical Luttinger-liquid in the edge of InAs/GaSb quantum spin Hall insulator, which shows characteristic suppression of conductance at low temperature and low bias voltage. Moreover, the conductance shows…

We study quantum point contacts in two-dimensional topological insulators by means of quantum transport simulations for InAs/GaSb heterostructures and HgTe/(Hg,Cd)Te quantum wells. In InAs/GaSb, the density of edge states shows an…

Helical edge modes are characteristic of topological insulators in two dimensions. This paper demonstrates that helical edge modes remain across transitions to ordinary insulators or to semimetals under certain condition. Straight and…

Quantum spin Hall devices with edges much longer than several microns do not display ballistic transport: that is, their measured conductances are much less than $e^2/h$ per edge. We imaged edge currents in InAs/GaSb quantum wells with long…

Electronic systems harboring one dimensional helical modes, where the spin and momentum of the electron are locked, have lately become an important field of its own. When coupled to a conventional superconductor, such systems are expected…

We report the electronic characterization of mesoscopic Hall bar devices fabricated from coupled InAs/GaSb quantum wells sandwiched between AlSb barriers, an emerging candidate for two-dimensional topological insulators. The electronic…