Conductance oscillation in surface junctions of Weyl semimetals

Abstract

Fermi arc surface states, the manifestation of the bulk-edge correspondence in Weyl semimetals, have attracted much research interest. In contrast to the conventional Fermi loop, the disconnected Fermi arcs provide an exotic two-dimensional (2D) system for exploration of novel physical effects on the surface of Weyl semimetals. Here, we propose that visible conductance oscillation can be achieved in planar junctions fabricated on the surface of a Weyl semimetal with a pair of Fermi arcs. It is shown that Fabry-Pérot-type interference inside the 2D junction can generate conductance oscillation with its visibility strongly relying on the shape of the Fermi arcs and their orientation relative to the strip electrodes, the latter clearly revealing the anisotropy of the Fermi arcs. Moreover, we show that the visibility of the oscillating pattern can be significantly enhanced by a magnetic field perpendicular to the surface taking advantage of the bulk-surface connected Weyl orbits. Our work offers an effective way to identify Fermi arc surface states through transport measurement and predicts the surface of Weyl semimetals as a novel platform for the implementation of 2D conductance oscillations.

Gate-Tunable Lifshitz Transition of Fermi Arcs and Its Transport Signatures

“…In particular, the topological Lifshitz transition [55] of FAs can be induced by surface decoration [53] or chemical potential modification, [54] which changes the sizes and shapes of the FAs, and especially, the way they connect pairs of Weyl nodes. The existing experiments show that FAs with different configurations can be realized in different samples, [52][53][54][56][57][58][59] but whether it is possible to continuously modify the FAs in a given sample remains an open question. It is of great interest to explore the possibility of manipulating FAs by external fields, in which both continuous deformation and abrupt Lifshitz transition of the FAs can be achieved.…”