TF-μSR Sensitivity to Charge Density Wave Order in 2H-NbSe2

Synopsis

The sensitivity of transverse-field muon spin rotation (TF-μSR) to static charge-density-wave (CDW) order in the bulk of 2H-NbSe2 is demonstrated. In the presence of CDW order, the quadrupolar interaction of the (93)Nb nuclei with the local electric-field gradient is modified, and this in turn affects the magnetic dipolar coupling of the positive muon to these nuclei. For a weak magnetic field applied parallel to the c-axis, we observe a small enhancement of the muon depolarization rate at temperatures below the established CDW phase transition. Aligning the applied field perpendicular to the c-axis, we observe a sensitivity to static CDW order in regions of the sample extending up to a temperature nearly 3 times the CDW transition temperature T(CDW). The results suggest that the muon is mobileover the temperature range explored above the superconducting transition temperature T(c), but becomes trapped in the vicinity of defects.