Evidence Hub

Correlated quantum shift vector of particle-hole excitations

Yang X, Srivastava A, Song JCW

Nature communications, 2026

Abstract

Excitons are a prime example of how electron interactions affect optical response and excitation. For example, electron-hole interactions produce a bound excitonic spectrum. Here we show that, beyond its spectra, the bound nature of an exciton's electron-hole pair produces a correlated quantum geometry: excitonic excitations possess a quantum shift vector that is independent of light polarization. We find this counterintuitive behavior has dramatic consequences for geometric response: e.g., in noncentrosymmetric but non-polar materials, vertical excitonic transitions possess vanishing shift vector zeroing their shift photocurrent; this contrasts with finite and strongly light polarization dependent shift vectors for non-interacting delocalized particle-hole excitations. This dichotomy makes shift vector a sharp diagnostic of the pair localization properties of particle-hole excitations and demonstrates the non-perturbative effects of electron interactions in excited state quantum geometric response.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free