Observation of double superconducting domes in multilayer tellurene under high pressure

Intensive investigation of elemental two-dimensional (2D) materials with anisotropic structures holds promise for unraveling novel physical phenomena and clarifying the relationship between dimensionality and superconductivity. Here, we successfully observed unprecedented double superconducting domes in a 2D elemental superconductor multilayer tellurene under high pressure. Upon compression, multilayer tellurene undergoes multiple structural phase transitions dissimilar with bulk tellurium, progressing from an initial hexagonal twofold $P{3}_{1}21$ phase to a quasi-2D monoclinic fourfold $P{2}_{1}$ phase and ultimately to the three-dimensional (3D) rhombohedral sixfold $R\overline{3}m$ and cubic eightfold $\mathit{Im}\overline{3}m$ structures. Moreover, low-temperature electrical resistance measurements demonstrate the emergence of superconductivity at 0.5 GPa with superconducting transition temperature (${T}_{\mathrm{c}}$) \ensuremath{\sim}2.9 K. The pressure-dependent ${T}_{\mathrm{c}}$ reveals an unexpected double-dome superconducting phase diagram alongside notably different upper critical fields that benefit from the combined effect of dimensional change and structural modulation. This work observed pressure-induced double-dome superconductivity in the elemental 2D materials, offering a promising pathway for achieving uncommon superconductivity behavior in 2D systems under extreme conditions.