Related papers: Electron-Phonon Coupling and Quantum Correction to…
We study coherent transport in density tunable micro-devices patterned from thin films of the topological insulator (TI) Bi2Se3. The devices exhibit pronounced electric field effect, including ambipolar modulation of the resistance with an…
We performed a Raman scattering study of thin films of LiTi$_2$O$_4$ spinel oxide superconductor. We detected four out of five Raman active modes, with frequencies in good accordance with our first-principles calculations. Three T$_{2g}$…
The strength of the electron-phonon coupling parameter and its evolution throughout a solid's phase diagram often determines phenomena such as superconductivity, charge- and spin-density waves. Its experimental determination relies on the…
A prominent band centered at around 1000-1300 cm-1 and associated with resonant enhancement of two-phonon Raman scattering is reported in multiferroic BiFeO3 thin films and single crystals. A strong anomaly in this band occurs at the…
The interface between two-dimensional topological Dirac states and an s-wave superconductor is expected to support Majorana bound states that can be used for quantum computing applications. Realizing these novel states of matter and their…
A magnetic torque method is proposed that probes the warping and mass gap of Dirac cone surface states in topological insulators like Bi2X3 (X=Se,Te). A rotating field parallel to the surface induces a paramagnetic moment in the helical…
Single-crystalline \beta-Ag2Se nanostructures, a new class of 3D topological insulators (TIs), were synthesized using the chemical vapor transport method. The topological surface states were verified by measuring electronic transport…
We investigate quantum transport in micrometer-sized single crystals of Bi$_4$Br$_4$, a material predicted to be a second-order topological insulator. 1D topological states with long phase coherence times are revealed via the modulation of…
Graphene-based multilayer systems serve as versatile platforms for exploring the interplay between electron correlation and topology, thanks to distinctive low-energy bands marked by significant quantum metric and Berry curvature from…
The optical properties of the superconducting single crystal Rb$_{0.8}$Fe$_{1.68}$Se$_2$ with $T_{c}$ $\simeq$ 31 K have been measured over a wide frequency range in the $ab$ plane. We found that the optical conductivity is dominated by a…
The recent discovery of non-saturating giant positive magnetoresistance in Td-WTe2 has aroused great interest in this material. We have studied the structural, electronic and vibrational properties of bulk and few-layer Td-WTe2…
We explore the Fano resonance in ZrTe5, using Raman scattering measurements. We identified two closely spaced B2g phonon modes, B2g I and B2g II, around 9 meV and 10 meV, respectively. Interestingly, only B2g I exhibited the Fano resonance,…
Nearly a decade after the discovery of topological insulators (TIs), the important task of identifying and characterizing their topological surface states through electrical transport experiments remains incomplete. The interpretation of…
The metallic surface states of a topological insulator support helical Dirac fermions protected by topology with their spin locked perpendicular to their momentum. They can acquire mass through magnetic doping or through hybridization of…
The semimetal NbIrTe4 has been proposed to be a Type-II Weyl semimetal with 8 pairs of opposite Chirality Weyl nodes which are very close to the Fermi energy. This topological electronic structure is made possible because of the broken…
Topological materials hosting kagome lattices have drawn considerable attention due to the interplay between topology, magnetism, and electronic correlations. The (Fe$_{1-x}$Co$_x$)Sn system not only hosts a kagome lattice but has a tunable…
We report on a >100-fold enhancement of Raman responses from Bi2Se3 thin films if laser photon energy switches from 2.33 eV (532 nm) to 1.58 eV (785 nm), which is due to direct optical coupling to Dirac surface states (SS) at the resonance…
Topological quantum materials coupled with magnetism can provide a platform for realizing rich exotic physical phenomena, including quantum anomalous Hall effect, axion electrodynamics and Majorana fermions. However, these unusual effects…
Quantum interference is studied in a three-band model of pseudospin-one fermions in the $\alpha-\mathcal{T}_3$ lattice. We derive a general formula for magnetoconductivity that predicts a rich crossover between weak localization (WL) and…
The magneto-electric (ME) coupling on spin-wave resonances in single-crystal Cu2OSeO3 was studied by a novel technique using electron spin resonance combined with electric field modulation. An external electric field E induces a magnetic…