Related papers: Enhanced Valley Polarization via Nonlinear Cascade…
Producing currents predominantly from a single valley, namely valley-polarized currents, at optical-cycle timescales is an important aspect of the petahertz valleytronics, yet it remains less developed. This work exhibits the feasibility of…
Nonlinear transport plays a vital role in probing the quantum geometry of Bloch electrons, valley chirality, and carrier scattering mechanisms. The nonlinear Hall effect, characterized by a nonlinear scaling of Hall voltage with…
We show that, because of the inevitable twist and lattice mismatch in heterobilayers of transition metal dichalcogenides, interlayer excitons have six-fold degenerate light cones anomalously located at finite velocities on the parabolic…
Valleytronics has emerged as a promising paradigm, enabling comprehensive control of the valley degree of freedom (DoF) for energy-efficient and high-speed information processing. However, backscattering-induced valley depolarization…
Valleytronics exploits non-equivalent energy extrema in the electronic band structure of crystalline solids -- the valley degree of freedom -- to encode, manipulate, and read out information. The advent of 2D materials, first graphene and…
Nonlinear light-matter interaction and, in particular, high-harmonic generation (HHG) are fundamentally interesting and frequently discussed as versatile probes of quantum materials with potential for optical information processing…
Alloyed transition metal dichalcogenides provide an opportunity for coupling band engineering with valleytronic phenomena in an atomically-thin platform. However, valley properties in alloys remain largely unexplored. We investigate the…
A recent scientific debate has arisen: Which processes underlie the actual ground of the valley Hall effect (VHE) in two-dimensional materials? The original VHE emerges in samples with ballistic transport of electrons due to the anomalous…
Semiconducting transition metal dichalcogenide monolayers have emerged as promising candidates for future valleytronics-based quantum information technologies. Two distinct momentum-states of tightly-bound electron-hole pairs in these…
We study the role of transition rule in high-order harmonic generation from solids driven by linearly polarized laser elds. The orientation-dependent transition dipoles can regulate the emergence of the multi-plateau structure. In the…
We develop multipolar theory of nonlinear generation of entangled photons from subwavelength dielectric particles due to the spontaneous parametric downconversion. We demonstrate that optical excitation in resonance with the high-quality…
Degenerate extrema in the energy dispersion of charge carriers in solids, also referred to as valleys, can be regarded as a binary quantum degree of freedom, which can potentially be used to implement valleytronic concepts in van der Waals…
The nonlinear optical response of a system of molecules often contains contributions whereby the products of lower-order processes in two separate molecules give signals that appear on top of a genuine direct higher-order process with a…
Two-dimensional hexagonal materials such as transition metal dichalcogenides exhibit valley degrees of freedom, offering fascinating potential for valley-based quantum computing and optoelectronics. In nonlinear optics, the K and K' valleys…
Valley, as a degree of freedom, has been exploited to realize valley-selective Hall transport and circular dichroism in two-dimensional layered materials. On the other hand, orbital angular momentum of light with helical phase distribution…
In multivalley systems, the valley pseudospin offers rich physics going from encoding of information by its polarization (valleytronics), to exploring novel phases of matter when its degeneracy is changed. Here, by strain engineering, we…
The nonlinear processes of frequency conversion like second harmonic generation (SHG) usually obey certain selection rules, resulting from the preservation of different kind of physical quantities, e.g., the angular momentum. For SHG…
We theoretically introduce the fundamentally fastest induction of a significant population and valley polarization in a monolayer of a transition metal dichalcogenide (i.e., $\mathrm{MoS_2}$ and $\mathrm{WS_2}$). This may be extended to…
Valley-contrasting Hall transport conventionally relies on the inversion symmetry breaking in two-dimensional systems, which greatly limits the selection range of valley materials. In particular, while monolayer transition metal…
The nonlinear optical behavior of quantum systems plays a crucial role in various photonic applications. This study introduces a novel framework for understanding these nonlinear effects by incorporating gauge-covariant formulations based…