# Orientation-dependent transition rule in high-order harmonic generation from solids

## TL;DR

This paper investigates how orientation-dependent transition rules influence high-order harmonic generation in solids, revealing synchronization and interference effects that can be used to image solid structures and optimize attosecond pulse production.

## Contribution

It introduces a new understanding of the role of transition rules and quantum-path interference in multi-plateau harmonic generation from solids.

## Key findings

- Orientation-dependent yields exhibit synchronization and fine patterns.
- Transition rules and quantum interference jointly shape harmonic emission.
- Proposed intercycle interference scheme aids solid structure imaging.

## Abstract

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 multi-plateau zone, however, di erent from the mechanisms of step-by-step excitation reported previously, we nd that the emission time and orientationdependent yields exhibit synchronization and more ne patterns, respectively. And the orientationdependent yields and its ne patterns can be attributed to the collective contribution of the transition rule and quantum-path interference. Therefore, to better understand the constructive and destructive patterns in the orientation-dependent yields, we propose a scheme of intercycle interference, which can further be utilized as a tool to image the structure of the solids and provide an avenue to optimize the electron dynamics in solids for the production of attosecond pulses in a compact setup.