Resonant tunneling diodes in semiconductor microcavities: modeling polaritonic features in the THz displacement current

TL;DR

This paper models the quantum transport in resonant tunneling diodes within optical cavities, revealing polaritonic features and Rabi oscillations, and introduces a new approach for analyzing high-frequency electron devices.

Contribution

It presents a simple quantum model capturing polaritonic effects in tunneling diodes under strong light-matter coupling, including a novel displacement current analysis for high-frequency regimes.

Findings

Resonant peaks split into polaritonic peaks due to electron-photon interaction.

Coherent Rabi oscillations observed among polaritonic states.

Traditional static transmission coefficients replaced by displacement current coefficients in AC analysis.

Abstract

We develop in this work a simple qualitative quantum electron transport model, in the strong light-matter coupling regime under dipole approximation, able to capture polaritonic signatures in the time-dependent electrical current. The effect of the quantized electromagnetic field in the displacement current of a resonant tunneling diode inside an optical cavity is analyzed. The original peaks of the bare electron transmission coefficient split into two new peaks due to the resonant electron-photon interaction, leading to coherent Rabi oscillations among the polaritonic states that are developed in the system in the strong coupling regime. This mimics known effects predicted by a Jaynes-Cummings model in closed systems, and shows how a full quantum treatment of electrons and electromagnetic fields may open interesting paths for engineering new THz electron devices. The computational burden involved in the multi-time measurements of THz currents is tackled by invoking a Bohmian description of the light-matter interaction. We also show that the traditional static transmission coefficient used to characterize DC quantum electron devices has to be substituted by a new displacement current coefficient in high-frequency AC scenarios.