Extended Data Fig. 6: Magnetic field tunability of the wavevector of the translational symmetry breaking order.
From: Topological excitonic insulator with tunable momentum order
a, Atomically resolved topographic image of a clean Ta2Pd3Te5 (100) surface acquired at T = 5 K. Inset shows the corresponding Fourier transform image displaying well-defined Bragg peaks (purple circles). b, Topographic image of the same region presented in panel a, acquired at T = 4.2 K and B = 0 T, revealing a pronounced translational symmetry breaking order. Inset: Fourier transform image displaying well-defined superlattice peaks (orange circles) alongside the Bragg peaks (purple circles). The extracted wavevector is \({Q}_{{\rm{exc}}}=\left[\right.\pm \left(-0.43{c}^{* }+0.035{b}^{* }\right),\)\(\pm \left(0.57{c}^{* }+0.035{b}^{* }\right)\left.\right]\). c–e, Topographic images from the same location but acquired at magnetic fields of 2 T, 4 T, and 6 T, respectively, highlighting a change in the translational symmetry breaking ordering pattern upon increasing the magnetic field. The Fourier transform images shown in the inset reveal a gradually evolving Qexc where Qexc changes to [\(\pm \left(-0.44{c}^{* }+0.051{b}^{* }\right),\pm \left(0.56{c}^{* }+0.051{b}^{* }\right)\)] at 2 T, [\(\pm \left(-0.47{c}^{* }+0.06{b}^{* }\right),\)\(\pm \left(0.53{c}^{* }+0.06{b}^{* }\right)\)] at 4 T, and \(\pm \left(0.5{c}^{* }+0.07{b}^{* }\right)\)] at 6 T. f, Polar plot summarizing the magnetic field tunability of Qexc. Starting from being incommensurate along both b- and c-axes at \(B=0\) T, Qexc evolves continuously and becomes commensurate along the c-axis at \(B=6\) T. Tunneling junction set-up: Vset = 300 mV, Iset = 0.5 nA.
