Publications (15)
Observation of a Helical Luttinger-Liquid in InAs/GaSb Quantum Spin Hall Edges
Tingxin Li, Pengjie Wang, Hailong Fu +8
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 temper…
Microwave Photocurrent from the Helical Edge state of InAs/GaInSb Bilayers
Jie Zhang, Tingxin Li, Rui-Rui Du +1
We measure microwave photocurrent in devices made from InAs/GaInSb bilayers where both insulating bulk state and conducting edge state were observed in the inverted-band regime, co…
Effective g-factors of carriers in inverted InAs/GaSb bilayers
Xiaoyang Mu, Gerard Sullivan, Rui-Rui Du
We perform tilt-field transport experiment on inverted InAs/GaSb which hosts quantum spin Hall insulator. By means of coincidence method, Landau level (LL) spectra of electron and…
Evidence for Helical Edge Modes in Inverted InAs/GaSb Quantum Wells
Ivan Knez, Rui-Rui Du, Gerard Sullivan
We present an experimental study of low temperature electronic transport in the hybridization gap of inverted InAs/GaSb composite quantum wells. Electrostatic gate is used to push…
Observation of Quantum Spin Hall States in InAs/GaSb Bilayers under Broken Time-Reversal Symmetry
Lingjie Du, Ivan Knez, Gerard Sullivan +1
Topological insulators (TIs) are a novel class of materials with nontrivial surface or edge states. Time-reversal symmetry (TRS) protected TIs are characterized by the Z2 topologic…
Localization of trivial edge states in InAs/GaSb composite quantum wells
Vahid Sazgari, Gerard Sullivan, Ä°smet Ä°. Kaya
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 hig…
Tuning Edge States in Strained-Layer InAs/GaInSb Quantum Spin Hall Insulators
Lingjie Du, Tingxin Li, Wenkai Lou +8
We report on a class of quantum spin Hall insulators (QSHIs) in strained-layer InAs/GaInSb quantum wells, in which the bulk gaps are enhanced by up to five folds as compared to the…
Resistive signature of excitonic coupling in an electron-hole double layer with a middle barrier
Xingjun Wu, Wenkai Lou, Kai Chang +2
We study the interlayer scattering mediated by long-range Coulomb interaction between electrons (density n) and holes (p) in a double-layer system. The gated device is made of InAs…
Gate-Tuned Spontaneous Exciton Insulator in Double-Quantum Wells
Lingjie Du, Wenkai Lou, Kai Chang +2
It was proposed that a dilute semimetal is unstable against the formation of an exciton insulator, however experimental confirmations have remained elusive. We investigate the orig…
Finite Conductivity in Mesoscopic Hall Bars of Inverted InAs/GaSb Quantum Wells
Ivan Knez, R. R. Du, Gerard Sullivan
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 gat…
Interaction-induced crossover between weak anti-localization and weak localization in a disordered InAs/GaSb double quantum well
Vahid Sazgari, Gerard Sullivan, Ismet I. Kaya
We present magneto-transport study in an InAs/GaSb double quantum well structure in the weak localization regime. As the charge carriers are depleted using a top gate electrode, we…
Low-Temperature Conductivity of Weakly Interacting Quantum Spin Hall Edges in Strained-Layer InAs/GaInSb
Tingxin Li, Pengjie Wang, Gerard Sullivan +2
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…
Anomalous Conductance Oscillations in the Hybridization Gap of InAs/GaSb Quantum Wells
Zhongdong Han, Tingxin Li, Long Zhang +2
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 b…
Images of edge current in InAs/GaSb quantum wells
Eric M. Spanton, Katja C. Nowack, Lingjie Du +3
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 per edge.…
Perfect Andreev Reflection of Helical Edge Modes in InAs/GaSb Quantum Wells
Ivan Knez, Rui-Rui Du, Gerard Sullivan
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…