Quantum anomaly and anomalous Josephson effect in inversion asymmetric Weyl semimetals

Abstract

We study a Josephson junction involving an inversion-asymmetric Weyl semimetal in presence of time-reversal symmetric (TRS) or time-reversal symmetry broken tilt in the Weyl spectra. We reveal that both types of tilts in the Weyl nodes lead to a Josephson $0$-$\pi$ transition and a zero bias valley/chiral supercurrent. Strikingly, the TRS tilt gives rise to a pure valley Josephson current (VJC) and TRS broken tilt induces a pure chirality Josephson current (CJC) in this system. The VJC and CJC are the manifestation of valley symmetry broken and ${\mathbb{Z}}_2$ symmetry broken by the respective tilt. We obtain the reversal of a pure VJC and pure CJC even in the zero bias condition controllable by the junction length. Our analysis of controllability of valley and chirality dependent transport in an inversion asymmetric Weyl semimetal junction could allow applications in valleytronics and chiralitytronics, respectively. The tilt induced Josephson effect provides an alternative route for supercurrent $0$-$\pi$ transition, different from the conventional ferromagnetism Josephson junctions where the spin polarization is essential. In the long junction and zero temperature limit, VJC and CJC are associated with a quantum anomaly which is manifested through a discontinuous jump in the current in absence of TRS and TRS breaking tilts, respectively.

10 pages, Appear in PRB

References in corpus (14)

• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Topological response in Weyl semimetals and the chiral anomaly
• Anomalous Hall Effect in Weyl Metals
• Direct coupling between magnetism and superconducting current in Josephson Phi junction
• Photocurrents in Weyl semimetals
• Weyl Node and Spin Texture in Trigonal Tellurium and Selenium
• Anomalous Josephson effect induced by spin-orbit interaction and Zeeman effect in semiconductor nanowires
• Quantum transport in Dirac materials: signatures of tilted and anisotropic Dirac and Weyl cones
• Fermion-parity anomaly of the critical supercurrent in the quantum spin-Hall effect
• Josephson effect in a Weyl SNS junction
• Andreev Reflection in Weyl Semimetals
• Mirror Anomaly in Dirac Semimetals
• Josephson junctions of Weyl and multi-Weyl semimetals
• Universal phase transition and band structures for spinless nodal-line and Weyl semimetals