Fig. 2: Characterization of the chiral structure of 1T-TaS2.
From: Spectroscopic visualization and phase manipulation of chiral charge density waves in 1T-TaS2
a Schematics of the two enantiomers (α and β) for the CDW superlattice structure. b, c The STM images of chiral CDW corresponding to α and β phases. The white star and yellow rhombus illustrate the David star structure and unit cell of the superlattice, respectively. d, e SAED results of two 1T-TaS2 samples with opposite chiral Raman response. Q1, Q2 (or \({{{{{{\bf{Q}}}}}}}_{1}^{{\prime} }\), \({{{{{{\bf{Q}}}}}}}_{2}^{{\prime} }\)) represent the reciprocal vectors of the atomic lattice. The diffraction spots in the triangular groups are from the CDW superlattice. f, g Schematic illustration of the SAED patterns for the NCCDW phases with opposite chirality. Solid dots and circles represent the diffraction spots of atomic lattice and CDW superlattice structure, respectively. q1, q2 (or \({{{{{{\bf{q}}}}}}}_{1}^{{\prime} }\), \({{{{{{\bf{q}}}}}}}_{2}^{{\prime} }\)) represent the reciprocal vectors of the CDW superlattice. φ and −φ are the rotation angles of the chiral CDW superlattices with respect to the atomic lattice. h, i SHG signals of two 1T-TaS2 samples with opposite chirality. j Variation of SHG intensity as a function of the polarization angle of the incident light.
