相关论文: Room-Temperature Topological Phase Transition in Q…
The exploration of topological quantum materials and topological phase transitions is at the forefront of modern condensed matter physics. Quasi-one-dimensional (quasi-1D) bismuth iodide Bi4I4 exhibits versatile topological phases of matter…
Quasi-1D materials Bi$_{4}$X$_{4}$ (X=Br,I) are prototype weak topological insulators (TI) in the $\beta$ phase. For the $\alpha$ phases, recent high-throughput database screening suggests that Bi$_{4}$Br$_{4}$ is a rare higher-order TI…
Topological phase transitions involving crystalline symmetry breaking provide a fertile ground to explore the interplay between symmetry, topology, and emergent quantum phenomena. Recently discovered quasi-one-dimensional topological…
The major breakthroughs in the understanding of topological materials over the past decade were all triggered by the discovery of the Z$_2$ topological insulator (TI). In three dimensions (3D), the TI is classified as either "strong" or…
Superconductivity and topological quantum states are two frontier fields of research in modern condensed matter physics. The realization of superconductivity in topological materials is highly desired, however, superconductivity in such…
We discuss possible topological phase transitions in Ge-based thin films of Ge(Bi$_x$Sb$_{1-x}$)$_2$Te$_4$ as a function of layer thickness and Bi concentration $x$ using the first principles density functional theory framework. The bulk…
The quasi-one-dimensional material Bi4I4 hosts two crystallographically similar polymorphs that realize distinct topological insulating phases separated by a first-order structural transition near room temperature. This transition occurs…
Topological physics and strong electron-electron correlations in quantum materials are typically studied independently. However, there have been rapid recent developments in quantum materials in which topological phase transitions emerge…
Topological phases, especially topological crystalline insulators (TCIs), have been intensively explored observed experimentally in three-dimensional (3D) materials. However, the two-dimensional (2D) films are explored much less than 3D…
The bismuth-halide Bi$_4$I$_4$ undergoes a structural transition around $T_P\sim 300$K, which separates a high-temperature $\beta$ phase ($T>T_P$) from a low-temperature $\alpha$ phase ($T<T_P$). $\alpha$ and $\beta$ phases are suggested to…
A system with equal number of positive and negative charges confined in a box with a small but finite thickness is modeled as a function of temperature using mesoscale numerical simulations, for various values of the charges. The Coulomb…
Ultra-cold atoms in 1D bi-chromatic lattices constitute a surprisingly simple system for the study of topological insulators. We show that topological phase transitions constitute a general feature of bosons in 1D bi-chromatic lattices, and…
Three-dimensional (3D) topological Dirac semimetal, when thinned down to 2D few layers, is expected to possess gapped Dirac nodes via quantum confinement effect and concomitantly display the intriguing quantum spin Hall (QSH) insulator…
Quasi-one-dimensional bismuth halides offer an exceptional platform for exploring diverse topological phases, yet the nature of the room-temperature topological phase transition in Bi$_4$I$_4$ remains unresolved. While theory predicts the…
The recently discovered three dimensional or bulk topological insulators are expected to exhibit exotic quantum phenomena. It is believed that a trivial insulator can be twisted into a topological state by modulating the spin-orbit…
Recent progress in the field of topological states of matter(1,2) has largely been initiated by the discovery of bismuth and antimony chalcogenide bulk topological insulators (TIs)(3-6), followed by closely related ternary compounds(7-16)…
We propose SnBi2Te4 to be a novel candidate material exhibiting temperature (T) mediated transitions between rich topological phases. From a combined theoretical and experimental studies, we find that SnBi2Te4 goes from a low-T topological…
Higher-dimensional topological phases play a key role in understanding the lower-dimensional topological phases and the related topological responses through a dimensional reduction procedure. In this work, we present a Dirac-type model of…
Topological insulators (TIs) are an important family of quantum materials that exhibit a Dirac point (DP) in the surface band structure but have a finite band gap in bulk. A large degree of spin-orbit interaction and low bandgap is a…
The Ge(001)-(2 1 0 3)-Pb surface reconstruction with a lead coverage of 5/3 monolayer is on the borderline between the low-coverage covalently-bonded and high-coverage metallic lead overlayers. This gives rise to an unusual low-temperature…