Wave-Function-Free Approach for Predicting Nonlinear Responses in Weyl Semimetals
Phys. Rev. Lett. 136, 046601 – Published 27 January, 2026
DOI: https://doi.org/10.1103/pgz6-thm6
Abstract
By sidestepping the intractable calculations of many-body wave functions, density functional theory has revolutionized the prediction of ground states of materials. However, predicting nonlinear responses—critical for next-generation quantum devices—still relies heavily on explicit wave functions, limiting computational efficiency. In this Letter, using the circular photogalvanic effect in Weyl semimetals as a representative example, we realize a 1000-fold computational speedup by eliminating the explicit dependence on wave functions. Our approach leverages the one-to-one correspondence between free parameters of Weyl fermions and the associated responses to obtain precise wave-function-free formulations. Applying our methodology, we systematically investigated known Weyl semimetals and revealed that exhibits photocurrents an order of magnitude greater than those observed in TaAs, with potential for an additional order-of-magnitude enhancement under strain. To further demonstrate the generality of our approach, we obtained a wave-function-free formula for the Berry-curvature dipole in Weyl semimetals. Our Letter paves the way for substantially more efficient screening and optimization of nonlinear electromagnetic properties in topological quantum materials.
