Electron-Electron Interaction and Weak Antilocalization Effect in a Transition Metal Dichalcogenide Superconductor

In disordered transition-metal dichalcogenide (TMD) superconductor, both the strong spin-orbit coupling (SOC) and the disorder show remarkable effects on superconductivity. However, the features of SOC and disorder are rarely detected directly. Herein, the quantum transport behaviors arising from the interplay of SOC and disorder in the TMD superconductor 1T-NbSeTe are reported. Before entering the superconducting state, the single crystal at low temperature shows a resistivity upturn, which is T (1/2) dependent and insensitive to the applied magnetic fields. The magnetoresistance (MR) at low temperatures shows an H (1/2) dependence at high magnetic fields. The characteristics are in good agreement with the electron-electron interaction (EEI) in a disordered conductor. In addition, the upturn changes and MR at low magnetic fields suggest the contribution of the weak antilocalization (WAL) effect arising from the strong SOC in the material. Moreover, the quantitative analyses of the transport features in different samples imply anomalous disorder-enhanced superconductivity that needs to be further understood. The results reveal the disorder-enhanced EEI and the strong SOC-induced WAL effect in 1T-NbSeTe, which illustrates the resistivity minimum in the widely studied doped superconductors. The work also provides insights into the disorder effect on superconductivity.