Related papers: Nonlinear optical responses in multi-orbital topol…
Heterostructures of two-dimensional transition metal dichalcogenides (TMDs) are emerging as a promising platform for investigating exotic correlated states of matter. Here, we propose to engineer Bose-Fermi mixtures in these systems by…
We study the nonlinear optical response in a superconducting NbN thin film with strong terahertz (THz)wave. Besides the expected third harmonic generation, we observe a new transient oscillation which softensin frequency with temperature…
Topological superconductors are a class of unconventional superconducting materials featuring sub-gap zero-energy Majorana bound modes that hold promise as a building block for topological quantum computing. In this work, we study the…
Monolayer transition metal dichalcogenide (TMD) semiconductors such as MoSe$_2$ host strongly bound excitons which are known to exhibit a strong resonant third-order nonlinear response. Although there have been numerous studies of the…
We investigate a phase-controllable mechanism for generating optical torque in a five-level double-tripod (DT) atom-light coupling scheme interacting with four strong coherent control fields as well as two weak optical vortex probe beams…
The transition metal dichalcogenide 4H$_{b}$-TaS$_{2}$ exhibits characteristics of topological edge modes and two-component superconductivity with time-reversal symmetry breaking (TRSB). The nature of the superconducting order parameter is…
We report the photoresponse of niobium diselenide (NbSe$_2$), a transition metal dichalcogenide (TMD) which exhibits superconducting properties down to a single layer. Devices are built by using micro-mechanically cleaved 2 to 10 layers and…
We develop a six-band $\mathbf{k} \cdot \mathbf{p}$ model to describe the electronic structure and optical response of chiral multifold semimetals, such as RhSi. By means of invariants method we construct the effective Hamiltonian…
Since the discovery of superconductivity in infinite-layer nickelates, there have been extensive efforts to unravel their electronic structure and pairing mechanism. In particular, understanding how the electronic structure evolves with…
Recently, concepts of topological phases of matter are extended to non-equilibrium systems, especially periodically driven systems. In this paper, we construct an example which shows non-equilibrium topological phase transitions using…
Analysis of the band structure of TiS$_3$ single-layers suggests the possibility of changing their physical behaviour by injecting electron carriers. The anisotropy of the valence and conduction bands is explained in terms of their complex…
Realizing strong nonlinear optical responses is a long-standing goal of both fundamental and technological importance. Recently significant efforts have focused on exploring excitons in solids as a pathway to achieving nonlinearities even…
Second-order nonlinear optical responses, including photogalvanic effect (PGE) and second harmonic generation (SHG), are important physical phenomena in nonlinear optics. The PGE (SHG) related to linearly and circularly polarized light are…
We explore topological electronic structure of magnetic phases in a multi-orbital Hubbard model with spin-orbit interactions. To account for more general antiferromagnetic orders that go beyond the collinear N\'eel order, two different…
We present a theoretical study of the optical response of a nonlinear oscillator formed by coupling a metal nanoparticle local surface plasmon resonance to excitonic degrees of freedom in a monolayer transition-metal dichalcogenide. We show…
Despite being usually considered two competing phenomena, charge-density-wave and superconductivity coexist in few systems, the most emblematic one being the transition metal dichalcogenide 2H-NbSe$_2$. This unusual condition is responsible…
A topological superconductor features at its boundaries and vortices Majorana fermions, which are potentially applicable for topological quantum computations. The scarcity of the known experimentally verified physical systems with…
We investigate two-dimensional trilayered quantum systems with multi-orbital conduction bands by focusing on the role played by the layer degree of freedom in setting the character of nodal line semimetals. The layer index can label the…
We present a reconfigurable topological photonic system consisting of a 2D lattice of coupled ring resonators, with two sublattices of site rings coupled by link rings, which can be accurately described by a tight-binding model. Unlike…
We establish a steady-state theory for nonlinear optical conductivity in pseudo-Hermitian systems. We derive compact formulas for the first and second order conductivity tensors in both the velocity and length gauges and prove their exact…