Coexistence and competition of multiple charge-density-wave orders in rare-earth tritellurides

The occurrences of collective quantum states, such as superconductivity (SC) and charge-or spin-density waves (CDWs or SDWs), are among the most fascinating phenomena in solids. To date, much effort has been made to explore the interplay between different orders, yet little is known about the relationship of multiple orders of the same type. Here we report optical spectroscopy study on CDWs in the rare-earth tritelluride compounds RTe3 (R = rare-earth elements). Besides the prior reported two CDW orders, the study reveals unexpectedly the presence of a third CDW order in the series, which evolves systematically with the size of R element. With increased chemical pressure, the first and third CDW orders are both substantially suppressed and compete with the second one by depleting the low-energy spectral weight. A complete phase diagram for the multiple CDW orders in this series is established.