Fig. 5: Scanning tunneling microscopy and spectroscopy investigation of rotation symmetry breaking in ScV₆Sn₆, and the comparison to KV₃Sb₅.

a Energy-dependent amplitudes of the three inequivalent CDW peaks (marked in the example Fourier transform in the inset) in ScV₆Sn₆. The overall shape of all three dispersion curves is nearly identical and largely overlaps one another. b Zoom-in on representative high-resolution dI/dV(r, V) maps showing the approximately rotationally symmetric real-space signature. c Energy-dependent amplitudes of the three inequivalent CDW peaks (marked in the example Fourier transform in the inset) in cousin kagome metal KV₃Sb₅. the dispersion of Q_c amplitude is noticeably different than the other two, Q_a and Q_b, that are nearly indistinguishable. d Representative dI/dV(r, V) maps showing a unidirectional real-space signature that breaks the six-fold symmetry. STM setup conditions: (a) I_set = 30 pA, V_sample = -100 mV, V_exc = 5 mV; (b) I_set = 100 pA, V_sample = 100 mV, V_exc = 2 mV; (c, d) I_set = 150 pA, V_sample = 10 mV, V_exc = 1 mV. Scale bars correspond to: (b) 1 nm; (d) 4 nm.