Coexistence of resistance oscillations and the anomalous metal phase in a lithium intercalated TiSe$_2$ superconductor

TL;DR

This study demonstrates the coexistence of resistance oscillations and an anomalous metallic phase in lithium-intercalated TiSe$_2$, revealing complex interactions between superconductivity, charge density waves, and electronic structure.

Contribution

It uncovers the spontaneous formation of superconducting arrays and the coexistence of resistance oscillations with an anomalous metal phase in Li$_x$TiSe$_2$, advancing understanding of their interplay.

Findings

Observation of magnetoresistance oscillations indicating periodic domains.

Detection of an anomalous metal with a resistance plateau below $T_c$.

Induction of a superconducting dome via ionic gating.

Abstract

Superconductivity and charge density wave (CDW) appear in the phase diagram of a variety of materials including the high - $T$$_c$ cuprate family and many transition metal dichalcogenides (TMDs). Their interplay may give rise to exotic quantum phenomena. Here, we show that superconducting arrays can spontaneously form in TiSe$_2$ - a TMD with coexisting superconductivity and CDW - after lithium ion intercalation. We induce a superconducting dome in the phase diagram of Li$_x$TiSe$_2$ by using the ionic solid-state gating technique. Around optimal doping, we observe magnetoresistance oscillations, indicating the emergence of periodically arranged domains. In the same temperature, magnetic field and carrier density regime where the resistance oscillations occur, we observe signatures for the anomalous metal - a state with a resistance plateau across a wide temperature range below the superconducting transition. Our study not only sheds further insight into the mechanism for the periodic electronic structure, but also reveals the interplay between the anomalous metal and superconducting fluctuations.