From Wavefunction Collapse to Superconductivity: Evolution of the Electronic State in Compressed GaNb4Se8

Yuejian Wang; Zhongyan Wu; K C Bhupendra; Dongzhou Zhang; Lin Wang; Sanjay V. Khare; Lilian Prodan; Vladimir Tsurkan

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arXiv · 2604.26203

From Wavefunction Collapse to Superconductivity: Evolution of the Electronic State in Compressed GaNb4Se8

Yuejian Wang·Zhongyan Wu·K C Bhupendra·Dongzhou Zhang·Lin Wang·Sanjay V. Khare·Lilian Prodan·Vladimir Tsurkan

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Abstract

Understanding how electronic transport evolves from localized to itinerant regimes in correlated cluster solids remains an important challenge in condensed-matter physics. Here we investigate the pressure-dependent transport properties of the lacunar spinel GaNb4Se8, a cluster Mott insulator at ambient conditions. At low pressures, the resistivity follows Efros-Shklovskii variable-range hopping, indicating Coulomb-gap-controlled carrier localization (x ~ 6.1 Angstrom). A crossover toward metallic transport begins near ~ 5 GPa, whereas a crystallographic transition from the cubic phase to a monoclinic C2 phase occurs at significantly higher pressure (~ 20 GPa), establishing a hierarchy characterized by the decoupling of electronic delocalization from structural symmetry change. At higher pressures, superconductivity (xi(0) ~ 80-90 Angstrom) emerges from the correlated metallic regime. These results identify GaNb4Se8 as a platform for studying correlation-controlled transport evolution in cluster-based solids.

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Yuejian Wang, Zhongyan Wu, K C Bhupendra, Dongzhou Zhang, Lin Wang, Sanjay V. Khare, Lilian Prodan, Vladimir Tsurkan. 2026-04-29. From Wavefunction Collapse to Superconductivity: Evolution of the Electronic State in Compressed GaNb4Se8. https://arxiv.org/abs/2604.26203

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