Dissipation-induced Half Quantized Conductance in One-dimensional Topological Systems

TL;DR

This paper reveals that dissipation can induce half-quantized conductance in one-dimensional topological systems, providing a new way to observe topological signatures through transport in open quantum systems.

Contribution

It demonstrates analytically that dissipation enables half-quantized conductance in 1D topological models, a phenomenon absent in non-dissipative systems.

Findings

Half-quantized conductance appears in the topologically nontrivial phase.

Dissipation and gain/loss channels are crucial for the effect.

The phenomenon is absent in trivial phases.

Abstract

Quantized conductance from topologically protected edge states is a hallmark of two-dimensional topological phases. In contrast, edge states in one-dimensional (1D) topological systems cannot transmit current across the insulating bulk, rendering their topological nature invisible in transport. In this work, we investigate the transport properties of the Su-Schrieffer-Heeger model with gain and loss, and show that the zero-energy conductance exhibits qualitatively distinct behaviors between the topologically trivial and nontrivial phases, depending on the hybridization and dissipation strengths. Crucially, we analytically demonstrate that the conductance can become half-quantized in the topologically nontrivial phase, a feature absent in the trivial phase. We further show that the half quantization predominantly originates from transport channels involving gain/loss and edge states. Our results uncover a new mechanism for realizing quantized transport in 1D topological systems and highlight the nontrivial role of dissipation in enabling topological signatures in open quantum systems.