Dimensional tuning and coexisting electronic orders in single-crystalline $$1T\text {-Cu}_x\text {TiSe}_2$$ quantum materials

Résumé

Abstract We report a detailed study of moderate-coupling superconductivity coexisting with charge-density-wave (CDW) order in single-crystalline $$1T\text {-Cu}_x\text {TiSe}_2$$ ( $$x = 0\text {--}0.1$$ ) down to $$60\text { mK}$$ . Millikelvin specific-heat measurements on underdoped samples reveal a sharp superconducting anomaly with a vanishing residual electronic specific heat coefficient ( $$\gamma _r \rightarrow 0$$ ) in the ground state, signaling a fully gapped superconducting state clear of uncondensed normal electrons. Concurrently, distinct thermodynamic anomalies near $$200\text { K}$$ and $$25\text { K}$$ confirm the robust persistence of CDW order in the undoped and underdoped regimes, respectively. Upper critical-field measurements display a nearly temperature-independent anisotropy, $$H_{\text {c2}}^{ab}/H_{\text {c2}}^c \simeq 1.7$$ , consistent with conventional single-gap s -wave pairing. Analysis of the reduced specific-heat jump, $$\Delta C_{\text {el}}/\gamma _n T_{\text {c}}$$ , alongside the Werthamer-Helfand-Hohenberg (WHH) framework, establishes moderate electron-phonon coupling ( $$\lambda _{\text {el-ph}} = 0.62$$ ) and conventional superconductivity coexisting with a partially suppressed CDW state. These findings present $$1T\text {-Cu}_x\text {TiSe}_2$$ as a clean model platform for investigating the systematic modulation of competing quantum phases via transition-metal intercalation, offering a strategic framework for the architectural design of low-dimensional functional electronics.

Citer ce document

Accès au document

Texte intégral en lecture en ligne, réservé aux abonnés SPHAERO et aux membres de l'institution. Se connecter

Auteur(s)

Statistiques

Consultations : 1

Téléchargements : 0