Extended Data Fig. 3: Suppression of symmetry breaking in QPI wave vectors at an intermediate temperature of about 30 K in Sn-doped CsV₃Sb₅.

(a) dI/dV(r, V = −5 mV) map taken over a 45 nm square region of the Sb-terminated surface of CsV₃Sb_4.98Sn_0.02, and (b) associated Fourier transform (FT). Atomic Bragg peaks are enclosed in black circles, while the blue arrows point along the unidirectional electron scattering features. (c) FTs of dI/dV(r, V) maps taken at 10 K, 20 K and 30 K over the same region of the sample in (a,b). (d) Energy-dependent FT linecut shown as a waterfall plot acquired along the red dashed line in (b). Wave vector q₂ is detectable within about +/−15 meV around the Fermi level. (e) Temperature-dependent FT linecuts along the red dashed lines in (b,c) normalized by subtracting the average FT ‘baseline’ away from any prominent peaks. We use 0.29 Å⁻¹ average transverse to and 0.04 Å⁻¹ average along the linecut direction to create curves shown in (e). STM setup condition: (a–c) V_sample = −5 mV, V_exc = 1 mV, I_set = 50 pA; (d) V_sample = 20 mV, V_exc = 1 mV, I_set = 400 pA.