2025/02/13 by Ardamon Sten, Sten, Ardamon, Paramita Dutta +4 · 2 citations
Engineering · Physics and Astronomy · #Condensed matter physics #Dissipation #Electrical engineering #Engineering #Insulator (electricity) #Josephson effect #Josephson energy #Josephson phase #Mechanical and Optical Resonators #Optoelectronics #Physics #Quantum and electron transport phenomena #Quantum mechanics #Superconductivity #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #cond-mat.mes-hall #cond-mat.other #cond-mat.supr-con
paper · pdf · open access · doi:10.21468/scipostphyscore.9.3.043
published in SciPost Physics Core 9(3) (SciPost.org)
openalex created_date 2025/02/15 · openalex publication_date 2026/07/22 · openalex updated_date 2026/07/30
The interplay between topological protection and dissipation constitutes a critical frontier in the realization of hybrid quantum devices. Here, we investigate the transport signatures in a dissipative topological insulator-based Josephson junction, a platform that directly probes the competition between quantum coherence and loss. We model dissipation by coupling a “lossy” metallic lead to the junction, described effectively by a non-Hermitian Hamiltonian derived using the Lindblad formalism. We observe that the junction exhibits an asymmetric complex Andreev spectrum, where the imaginary energy component imposes a finite lifetime on the quasi-bound states. Furthermore, beyond specific phase intervals, the real component of the spectrum bifurcates: one branch merges with the continuum, while the other lies within the superconducting gap. Crucially, the characteristic zero-energy crossing shifts away from φ=π <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mi>ϕ</mml:mi> <mml:mo>=</mml:mo> <mml:mi>π</mml:mi> </mml:mrow> </mml:math> and acquires a non-zero imaginary component; consequently, the associated Majorana bound states acquire a finite lifetime, signaling a loss of robustness against dissipation. Finally, this spectral asymmetry drives an anomalous supercurrent, manifested as a non-vanishing current at zero phase difference. Our results reveal how dissipation fundamentally reshapes superconducting transport in topological junctions, opening new directions for dissipation-engineered quantum devices.