Related Experiment Video
Updated: May 17, 2026

Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
Correlated quantum shift vector of particle-hole excitations
Xu Yang1, Ajit Srivastava2, Justin C W Song3
1Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
None:
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.
Related Concept Videos
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
π Electron Effects on Chemical Shift: Overview
¹H NMR Signal Multiplicity: Splitting Patterns
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule
Quantum Numbers
The Pauli Exclusion Principle
