相关论文: Excitonic Instability in Ta2Pd3Te5 Monolayer
Two-dimensional (2D) moire materials provide a new solid-state platform with unprecedented controllability for studies of correlated quantum phenomena. To date, experimental studies have focused on the correlated electronic states; the…
Ta$_2$NiSe$_5$ continues to draw interest for its 326 K phase transition, whose dual electronic and structural nature reflects a complex interplay of electron-hole (excitonic) and electron-lattice interactions. Most studies that have…
Artificial moir\'e superlattices in 2d van der Waals heterostructure is a new venue for realizing and controlling correlated electronic phenomena. Recently, twisted bilayer WSe$_2$ emerged as a new robust moir\'e system hosting a correlated…
The electronic band structure of V$_2$O$_5$ is calculated using an all-electron quasiparticle self-consistent (QS) $GW$ method, including electron-hole ladder diagrams in the screening of $W$. The optical dielectric function calculated with…
Excitonic insulators host the condensates of bound electron-hole pairs, offering a platform for studying correlated bosonic quantum states. Yet, how macroscopic coherence emerges from locally collapsed pairing remains elusive. Here, using…
Monolayers of transition metal dichalcogenides (TMDCs) feature exceptional optical properties that are dominated by excitons, tightly bound electron-hole pairs. Forming van der Waals heterostructures by deterministically stacking individual…
The three-chain Hubbard model for Ta$_2$NiSe$_5$ known as a candidate material for the excitonic insulator is investigated over the wide range of energy gap $D$ between the two-fold degenerate conduction bands and the nondegenerate valence…
Twisted multilayer transition metal dichalcogenides (TMDs) are a promising platform for realizing topological exciton phases. Here we propose that twisted TMD heterotrilayers WX$_2$/MX$_2$/WX$_2$ with layer symmetry represents a realistic…
We present thermoelectric properties of Be$_2$C monolayer based on density functional theory and semi-classical Boltzmann transport theory. Electronic structure calculations predict this material as a semiconductor with a direct bandgap of…
Van der Waals heterostructures based on TMDC semiconducting materials have emerged as promising materials due to their spin-valley properties efficiently contrived by the stacking-twist angle. The twist angle drastically alters the…
Vertically stacked van der Waals structures are promising platforms that enable layer engineering, opening new avenues for the quantum control of elementary excitations, including optically generated bound electron-hole pairs. Here we…
When monolayers of two-dimensional (2D) materials are stacked into van der Waals structures, interlayer electronic coupling can introduce entirely new properties, as exemplified by recent discoveries of moir\'e bands that host highly…
The excitonic insulator Ta$_2$NiSe$_5$ experiences a first-order structural transition under pressure from rippled to flat layer-structure at Ps = 3 GPa, which drives the system from an almost zero-gap semiconductor to a semimetal. The…
The capability to switch electrically between superconducting and insulating states of matter represents a novel paradigm in the state-of-the-art engineering of correlated electronic systems. An exciting possibility is to turn on…
We present a first-principles study based on density functional theory (DFT) on the electronic and structural properties of Ta2NiSe5, a layered transition metal chalcogenide that has been considered as a possible candidate for an excitonic…
Twisted van der Waals heterostructures and the corresponding superlattices, moire superlattices, are remarkable new material platforms, in which electron interactions and excited-state properties can be engineered. Particularly, the band…
Van der Waals heterostructures of two-dimensional transition metal dichalcogenides provide a unique platform to engineer optoelectronic devices tuning their optical properties via stacking, twisting, or straining. Using ab initio Many-Body…
Stacking monolayers of transition metal dichalcogenides into a heterostructure with a finite twist-angle gives rise to artificial moir\'e superlattices with a tunable periodicity. As a consequence, excitons experience a periodic potential,…
Ta$_2$NiSe$_5$ is an excitonic insulator candidate showing the semiconductor/semimetal-to-insulator (SI) transition below $T_{\text{c}}$ = 326 K. However, since a structural transition accompanies the SI transition, deciphering the role of…
Magnetic topological insulators (TI) provide an important material platform to explore quantum phenomena such as quantized anomalous Hall (QAH) effect and Majorana modes, etc. Their successful material realization is thus essential for our…