Weak Pinning and Hexatic Order in a Doped Two-Dimensional Charge-Density-WaveSystem

摘要

Scanning-tunneling microscopy has been used to characterize the effects of Nbimpurities on the incommensurate charge-density-wave (CDW) phase in 1T-TaS Real and reciprocal-space data indicate that disorder in the CDW is due to dislocations and small random rotations of the CDW. The dislocations destroy translational order; however, calculations show that the orientational order is long range. These results are consistent with weak pinning and suggest the possibility of a hexatic CDW phase. The similarity of our data to results obtained for other two-dimensional systems is discussed. charge density wave, weak pinning, scanning tunneling microscopy, metal doped, hexatic order, impurity, melting.