Light–matter interaction in 2D and topological materials provides a fascinating control knob
for inducing emergent, non-equilibrium properties and achieving new functionalities in the …

In noncentrosymmetric materials, the responses (for example, electrical and optical)
generally depend on the direction of the external stimuli, called nonreciprocal phenomena …

Quantum geometry in condensed-matter physics has two components: the real part quantum
metric and the imaginary part Berry curvature. Whereas the effects of Berry curvature have …

A central result in superconductivity is that flat bands, though dispersionless, can still host a
nonzero superfluid weight due to quantum geometry. We show that the derivation of the …

For many materials, a precise knowledge of their dispersion spectra is insufficient to predict
their ordered phases and physical responses. Instead, these materials are classified by the …

Detecting the orientation of the Néel vector is a major research topic in antiferromagnetic
spintronics. Here we recognize the intrinsic nonlinear Hall effect, which is independent of the …

The geometry of quantum states is well established as a basis for understanding the
response of electronic systems to static electromagnetic fields, as exemplified by the theory …

We study the low-frequency properties of the bulk photovoltaic effect in topological
semimetals. The bulk photovoltaic effect is a nonlinear optical effect that generates dc …

Nonlinear responses are actively studied as probes of topology and band geometric
properties of solids. Here, we show that second harmonic generation serves as a probe of …

Rectified electric current induced by irradiating light, a so-called photocurrent, is an
established phenomenon in optoelectronic physics. In this paper, we present a …