Tunable discrete scale invariance in transition-metal pentatelluride flakes

TL;DR

This paper reports the observation of tunable discrete scale invariance in transition-metal pentatelluride flakes, demonstrating many-body effects and providing insights into Coulomb interactions in quantum materials.

Contribution

It reveals how reducing flake thickness tunes the scale factor of DSI, highlighting many-body effects and explaining oscillation cut-offs via screening effects.

Findings

Tunable log-periodic oscillations observed in ZrTe5 and HfTe5 flakes.

Reduction in scale factor due to decreased vacuum polarization.

Quantitative explanation of oscillation cut-offs through Thomas-Fermi screening.

Abstract

Log-periodic quantum oscillations discovered in transition-metal pentatelluride give a clear demonstration of discrete scale invariance (DSI) in solid-state materials. The peculiar phenomenon is convincingly interpreted as the presence of two-body quasi-bound states in a Coulomb potential. However, the modifications of the Coulomb interactions in many-body systems having a Dirac-like spectrum are not fully understood. Here, we report the observation of tunable log-periodic oscillations and DSI in ZrTe5 and HfTe5 flakes. By reducing the flakes thickness, the characteristic scale factor is tuned to a much smaller value due to the reduction of the vacuum polarization effect. The decreasing of the scale factor demonstrates the many-body effect on the DSI, which has rarely been discussed hitherto. Furthermore, the cut-offs of oscillations are quantitatively explained by considering the Thomas-Fermi screening effect. Our work clarifies the many-body effect on DSI and paves a way to tune the DSI in quantum materials.