Fig. 3: PDW state with C3 rotational symmetry-breaking in AC-CDW region.
From: Directly visualizing nematic superconductivity driven by the pair density wave in NbSe2
a–c Simultaneously obtained tunneling spectra maps dI/dV(r, V) ≡ g(r, E = eV) taken at −1.50, −1.32, −1.00 meV respectively, showing the quite different LDOS in such small energy interval. Scale bar: 0.5 nm. d The corresponding topography T(r) of AC-CDW order in (a–c). Scale bar: 0.5 nm. e SC gap map Δ(r) extracted from tunneling spectra maps. Scale bar: 0.5 nm. White dashed circles in (a–e) mark the AC-CDW crest configuration. f The Δ(r) line-profiles taken along three symmetric lines, L1, L2 and L3 as marked in (e). The Δ(r) amplitude along L3 is clearly larger compared to other two directions (L1 and L2). g The averaged Δ(r) along three symmetric directions (D1, D2 and D3 in the inset) extracted from all the crests in (e). h Histograms of local averaged SC gap size Δ in areas A1, A2 and A3 around all crests in (e). An example of the definition of A1, A2 and A3 is shown in the inset. Vertical dashed lines indicate the overall averaged gap value for A1, A2 and A3, respectively. Black arrows indicate the ±standard deviation. The results in (f-h) all show the C3 rotational symmetry-breaking of PDW state. Experimental setpoints in (a–d): Vs = −4 mV, It = 400 pA.
