Exploring Strain-Induced Topological Phase Transitions and Charge Density Wave Modulation in Weyl Semimetals Using a High-Strain Biaxial Device

Strain engineering has become an essential tool for tuning material properties, particularly in the context of topological phases. Commercial strain devices, however, typically allow for a maximum strain of ~1.5%, limiting the scope of such studies. Recent experiments on HfTe5 under uniaxial strain up to 5% [1] have demonstrated a phase transition from a weak topological insulator (WTI) to a strong topological insulator (STI), highlighting the potential of high strain devices as tool to study quantum materials. In this talk we will present our development of a variable biaxial strain device that exceeds 5% strain, significantly expanding the strain range available for experimental investigation. We validated the device's functionality through Multiphysics simulations and resistive strain gauges, confirming its effectiveness. We will discuss our application of the device to study (TaSe4)2I, a Weyl semimetal that exhibits charge density waves (CDW) to explore a potential topological phase transition at Weyl points. These experiments advance the understanding of strain-induced topological transitions and CDW modulation in quantum materials, offering new insights into the interplay between strain and topological phases.

[1] Liu, J., Zhou, Y., Yepez Rodriguez, S. et al. Nat Commun 15, 332 (2024).