Spectroscopic evidence of topological phase transition in 3D Dirac semimetal Cd$_3$(As$_{1-x}$P$_x$)$_2$

S. Thirupathaiah; I. Morozov; Y. Kushnirenko; A. V. Fedorov; E. Haubold; T. K. Kim; G. Shipunov; A. Maksutova; O. Kataeva; S. Aswartham; B. Büchner; S. V. Borisenko

doi:10.1103/PhysRevB.98.085145

paper

Spectroscopic evidence of topological phase transition in 3D Dirac semimetal Cd $_{3}$ (As $_{1 - x}$ P $_{x}$ ) $_{2}$

arXiv:1802.04045 · doi:10.1103/PhysRevB.98.085145

Abstract

We study the low-energy electronic structure of three-dimensional Dirac semimetal, Cd $_{3}$ (As $_{1 - x}$ P $_{x}$ ) $_{2}$ [ $x$ = 0 and 0.34(3)], by employing the angle-resolved photoemission spectroscopy (ARPES). We observe that the bulk Dirac states in Cd $_{3}$ (As $_{0.66}$ P $_{0.34}$ ) $_{2}$ are gapped out with an energy of 0.23 eV, contrary to the parent Cd $_{3}$ As $_{2}$ in which the gapless Dirac states have been observed. Thus, our results confirm the earlier predicted topological phase transition in Cd $_{3}$ As $_{2}$ with perturbation. We further notice that the critical P substitution concentration, at which the two Dirac points that are spread along the $c$ -axis in Cd $_{3}$ As $_{2}$ form a single Dirac point at $Γ$ , is much lower [x $_{c}$ (P) $<$ 0.34(3)] than the predicted value of x $_{c}$ (P)=0.9. Therefore, our results suggest that the nontrivial band topology of Cd $_{3}$ As $_{2}$ is remarkably sensitive to the P substitution and can only survive over a narrow substitution range, i.e., 0 $\leq$ x (P) $<$ 0.34(3).

3 figures, 5 pages

Spectroscopic evidence of topological phase transition in 3D Dirac semimetal Cd3​(As1−x​Px​)2​

Abstract

Spectroscopic evidence of topological phase transition in 3D Dirac semimetal Cd $_{3}$ (As $_{1 - x}$ P $_{x}$ ) $_{2}$