Dissipative Effects in Macroscopic Quantum Tunnelling and Microwave Modulation Transfer

ABSTRACT

In this work, we introduce an alternative framework for describing dissipative effects in macroscopic quantum tunnelling (MQT) and microwave modulation transfer. We analyse how environmental dissipation modifies dynamics and observable timescales in these two microwave‐frequency contexts, revisiting transmission‐line and resistive‐load models within the bounce (path‐integral) formalism and introducing a complementary Brownian‐motion (statistical‐trajectory) description for modulation‐transfer phenomena. While remaining consistent with established approaches, such as the transmission‐line model and the Leggett prescription, the proposed formulation provides a unified and operational perspective that facilitates the interpretation of experimental data and the identification of effective dissipation mechanisms. Applied to previously published measurements, the framework shows quantitative agreement while offering a physically transparent and practically accessible tool for modelling dissipation in microwave and quantum devices. Beyond its consistency with existing models, the approach is particularly advantageous in systems where dissipation is effectively distributed or non‐local, providing a simplified and physically transparent description in regimes where standard treatments may be less intuitive. These features suggest its potential relevance for the analysis and design of systems in which environmental coupling plays a critical role.