Data for: Isostructural electronic transition in MoS2 probed by solid-state high harmonic generation spectroscopy

Studying materials under extreme pressure in diamond anvil cells (DACs) is key to discovering emergent states of matter, yet no method currently allows the direct measurement of the electronic structure in this environment. Solid-state high harmonic generation (sHHG) offers a unique all-optical window into the electronic structure of materials. We demonstrate sHHG spectroscopy inside a DAC by probing 2𝑯-MoS2, up to 30 GPa, revealing a pressure-induced crossover of the lowest direct bandgap from the K-point to the 𝚪-point. This transition manifests as a sharp minimum in harmonic intensity and a 30° rotation of the sHHG polarization anisotropy, despite the absence of a structural phase change. First principles simulations attribute these features to interference between competing excitation pathways at distinct points in the Brillouin zone. Our results establish sHHG as a sensitive probe of electronic transitions at high pressure, enabling access to quantum phenomena that evade detection ..., , # Data Set For: Isostructural electronic transition in MoS~2~ probed by solid-state high harmonic generation spectroscopy

Dataset DOI: [10.5061/dryad.hx3ffbgsq](https://doi.org/10.5061/dryad.hx3ffbgsq)

## Description of the data and file structure

**Data Set For: Isostructural electronic transition in MoS2 probed by solid-state high harmonic generation spectroscopy**

This data set contains all raw data and scripts for analysis of the data.

**Description of the data and file structure:**

The data repository contains subfolders corresponding to each figure that contains the raw data for that figure. Subfolder and file names are descriptive and note the critical parameter (most often pressure) that is varied between data files in each figure. An additional folder contains functions written in Matlab that were used for analysis of the raw data. Beyond basic functions used in analysis as described for each figure, the function “loadSHHGanisotropy.m” is a useful tool in applying some of..., ,