arXiv subjects

M. Salado-Mejía

Publications and source records attributed to M. Salado-Mejía.

3 recordsLinked to original sources

arXiv2026

A first approach to the open dynamics of bipartite systems

In this work, we review the open quantum dynamics of the most known bipartite systems, such as the qubit-qubit system, the oscillator-oscillator system, and the qubit-oscillator system. First, we compare each system with and without rotating wave approximation. In this analysis, we observe the influence of the counter-rotating term in the system dynamics. Also, we compare and analyze the resulting dynamics of the three bipartite systems where, due to the nature of each system, different dynamics are observed, but some similarities are also observed between them. To obtain the system dynamics, we use the same platform, the Qutip Toolbox starting from the phenomenological master equation of each system. We made the latter have the same platform for comparison. We attach the codes to generate these dynamics.

quant-ph↗

arXiv2025

Thermodynamic decoupling in the deep-strong coupling regime

In the deep-strong coupling (DSC) regime, the interaction between light and matter exceeds their bare frequencies, leading to an effective decoupling. Theoretical and experimental evidence for this behavior has relied solely on measurements of local observables at equilibrium. However, such a local approach is insufficient to accurately describe energy fluxes in critical and nonequilibrium phenomena. Here, we use a two-terminal quantum junction to derive a thermodynamically consistent global master equation. We demonstrate that the associated heat current, a key nonlocal observable in any quantum thermal machine, also approaches zero in this extreme coupling scenario, underscoring the role of virtual photons in the vacuum ground state. Our results indicate that the decoupling is a more general feature of the DSC regime, with implications for quantum thermotronics.

quant-ph↗

arXiv2021

Spectroscopy and critical quantum thermometry in the ultrastrong coupling regime

We present an exact analytical solution of the anisotropic Hopfield model, and we use it to investigate in detail the spectral and thermometric response of two ultrastrongly coupled quantum systems. Interestingly, we show that depending on the initial state of the coupled system, the vacuum Rabi splitting manifests significant asymmetries that may be considered spectral signatures of the counterintuitive decoupling effect. Using the coupled system as a thermometer for quantum thermodynamics applications, we obtain the ultimate bounds on the estimation of temperature that remain valid in the ultrastrong coupling regime. Remarkably, if the system performs a quantum phase transition, the quantum Fisher information exhibits periodic divergences, suggesting that one can have several points of arbitrarily high thermometric precision for such a critical quantum sensor.

quant-ph↗