相关论文: Field-effect mobility enhanced by tuning the Fermi…
In an ideal bulk topological-insulator (TI) conducting surface states protected by time reversal symmetry enfold an insulating crystal. However, the archetypical TI, Bi2Se3, is actually never insulating; it is in fact a relatively good…
The emergence of topological order in graphene is in great demand for the realization of quantum spin Hall states. Recently, it is theoretically proposed that the spin textures of surface states in topological insulator can be directly…
The electric field induced quantum phase transition from topological to conventional insulator has been proposed as the basis of a topological field effect transistor [1-4]. In this scheme an electric field can switch 'on' the ballistic…
Combined in-situ x-ray photoemission spectroscopy, scanning tunnelling spectroscopy and angle resolved photoemission spectroscopy of molecular beam epitaxy grown Bi2Te3 on lattice mismatched substrates reveal high quality stoichiometric…
We characterize the topological insulator Bi$_2$Se$_3$ using time- and angle- resolved photoemission spectroscopy. By employing two-photon photoemission, a complete picture of the unoccupied electronic structure from the Fermi level up to…
We report semiconductor to metal-like crossover in temperature dependence of resistivity ($\rho$) due to the switching of charge transport from bulk to surface channel in three-dimensional topological insulator…
We have grown single-crystal BiSbTe3 3D TI sample and studied structural, TE as well as pressure dependent magneto-transport properties. Large positive Seebeck coefficient confirmed the p-type nature of BiSbTe3, which is consistent with…
Band structure engineering and interfacial buffer layers have been demonstrated as effective means to tune the Fermi level in topological insulators (TI). In particular, the charge compensated compound (BixSb1-x)2Te3 (BST) plays a critical…
Spin momentum locking is a key feature of the topological surface state, which plays an important role in spintronics. The electrical detection of current-induced spin polarization protected by the spin momentum locking in non-magnetic…
Topological insulators (TIs) are a new quantum state of matter. Their surfaces and interfaces act as a topological boundary to generate massless Dirac fermions with spin-helical textures. Investigation of fermion dynamics near the Dirac…
We report on infrared (IR) optical experiments on Bi$_2$Te$_3$ and Mn-doped Bi$_2$Te$_3$ epitaxial thin films. In the latter film, dilute Mn doping (4.5\%) of the topologically nontrivial semiconductor host results in…
We have studied the energy dispersion of the Dirac bands of the topological insulator Bi2Se3 at large parallel momenta using a setup for laser-based time-resolved momentum microscopy with 6 eV probe-photons. Using this setup, we can probe…
We study the temperature dependence ($77$ K - $475$ K) of the longitudinal resistivity and Hall coefficient of thin films (thickness $20$ nm) of three dimensional topological Dirac semimetal Na$_3$Bi grown via molecular beam epitaxy (MBE).…
Dirac fermions play a central role in the study of topological phases, for they can generate a variety of exotic states, such as Weyl semimetals and topological insulators. The control and manipulation of Dirac fermions constitute a…
Ultrathin (~3 quintuple layer) field-effect transistors (FETs) of topological insulator Bi2Se3 are prepared by mechanical exfoliation on 300nm SiO2/Si susbtrates. Temperature- and gate-voltage dependent conductance measurements show that…
Scanning tunneling spectroscopic studies of Bi2Se3 epitaxial films on Si (111) substrates reveal highly localized unitary impurity resonances associated with non-magnetic quantum impurities. The strength of the resonances depends on the…
Topological insulators(1-8) are a novel form of matter which features metallic surface states with quasirelativistic dispersion similar to graphene(9). Unlike graphene, the locking of spin and momentum and the protection by time-reversal…
A field-effect transistor that employs a perovskite-type SrTiO3 single crystal as the semiconducting channel is revealed to function as n-type accumulation-mode device with characteristics similar to that of organic FET's. The device was…
A WSe2 monolayer of 1T' phase is a large band gap quantum spin Hall insulator, supporting dissipationless charge and spin transports through the topologically protected edge states. In this work, we explore the nanoribbon forms of 1T' phase…
Defect engineering can improve the linked charge, spin, and lattice behavior of thermoelectric topological insulators. Using density functional theory with spin orbit coupling, we study structural, electronic, optical, thermoelectric,…