Observation of strange metal in hole-doped valley-spin insulator

TL;DR

This study reports the discovery of a strange metal phase in hole-doped V-doped WSe2, characterized by linear resistance and strong correlations, suggesting new pathways for superconductivity in 2D materials with spin-orbit coupling.

Contribution

First observation of a strange metal phase in a hole-doped valley-spin insulator, expanding understanding of correlated states in 2D materials with strong spin-orbit coupling.

Findings

Strange metal behavior observed at a critical carrier concentration.

Magnetoresistance is nearly linearly proportional to magnetic field.

The gamma/alpha ratio differs from known high-Tc superconductors.

Abstract

Temperature-linear resistance at low temperatures in strange metals is an exotic characteristic of strong correlation systems, as observed in high-TC superconducting cuprates, heavy fermions, Fe-based superconductors, ruthenates, and twisted bilayer graphene. Here, we introduce a hole-doped valley-spin insulator, V-doped WSe2, with hole pockets in the valence band. The strange metal characteristic was observed in VxW1-xSe2 at a critical carrier concentration of 9.5 x 10^20 cm-3 from 150 K to 1.8 K. The unsaturated magnetoresistance is almost linearly proportional to the magnetic field. Using the ansatz R(H,T) - R(0,0) ~ [(alpha.k.T)^2+(gamma.mu.B)^2]^1/2, the gamma/alpha ratio is estimated approximately to 4, distinct from that for the quasiparticles of LSCO, BaFe2(As1-xPx)2 (gamma/alpha=1) and bosons of YBCO (gamma/alpha=2). Our observation opens up the possible routes that induce strong correlation and superconductivity in two-dimensional materials with strong spin-orbit coupling.