arXiv subjects

Hanz Y. Ramírez

Publications and source records attributed to Hanz Y. Ramírez.

6 recordsLinked to original sources

arXiv2020

Thermal effects on the resonance fluorescence of doubly dressed artificial atoms

In this work, robustness of controlled density of optical states in doubly driven artificial atoms is studied under phonon dissipation. By using both perturbative and polaron approaches, we investigate the influence of carrier-phonon interactions on the emission properties of a two-level solid-state emitter, simultaneously coupled to two intense distinguishable lasers. Phonon decoherence effects on the emission spectra are found modest up to neon boiling temperatures ($\sim 30$ K), as compared with photon generation at the Fourier transform limit obtained in absence of lattice vibrations (zero temperature). These results show that optical switching and photonic modulation by means of double dressing, do not require ultra low temperatures for implementation, thus boosting its potential technological applications.

quant-ph↗

arXiv2018

Dipolariton formation in quantum dot molecules strongly coupled to optical resonators

In this theoretical work, we study a double quantum dot interacting strongly with a microcavity, while undergoing resonant tunneling. Effects of interdot tunneling on the light-matter hybridized states are determined, and tunability of their brightness degrees and associated dipole moments is demonstrated. These results predict dipolariton generation in artificial molecules coupled to optical resonators, and provide a promising scenario for control of emission efficiency and coherence times of exciton polaritons.

quant-ph↗

arXiv2018

A solid state emitter embedded in a microcavity under intense excitation: a variational master equation approach

In this work, dissipative effects from a phonon bath on the resonance fluorescence of a solid state two level system embedded in a high quality semiconductor microcavity and driven by an intense laser, are investigated. Within the density operator formalism, we derive a variational master equation valid for broader ranges of temperatures, pumping rates, and radiation-matter couplings, than previous studies. From the obtained master equation, fluorescence spectra for various thermal and exciting conditions are numerically calculated, and compared to those computed from weak coupling and polaronic master equations, respectively. Our results evidence the break down of those rougher approaches under increased temperature and strong pumping.

cond-mat.mes-hall↗

arXiv2016

Efficiently tunable photon emission from an optically driven artificial molecule

In this work, we investigate the emission properties of double quantum dot driven by a monochromatic electromagnetic field, while undergoing resonant tunneling and dissipation by phonons. We found emission spectra for both cases, with and without phonons, whose comparison allows to determine the dissipative effects. On the basis of the obtained results we propose efficient control of the resonance fluorescence of an artificial molecule, suitable for optoelectronic applications.

quant-ph↗

arXiv2013

Double Dressing and Manipulation of the Photonic Density of States in Nanostructured Qubits

In this work, a model to study the coupling between a semiconductor qubit and two timedependent electric fields is developed. By using it in the resonantly monochromatic double dressing regime, control of the local density of optical states is theoretically and numerically demonstrated for a strongly confined exciton. Drastic changes in the allowed energy transitions yielding tunable broadening of the optically active frequency ranges, are observed in the simulated emission spectra. The presented results are in excellent qualitative and quantitative agreement with recent experimental observations.

cond-mat.mes-hall↗

arXiv2008

Analytical obtention of eigen-energies for lens-shaped quantum dot with finite barriers

The bound states of a particle in a lens-shaped quantum dot with finite confinement potential are obtained in the envelope function approximation. The quantum dot has circular base with radius $a$ and maximum cap height $b$, and the effective mass of the particle is considered different inside and outside the dot. A 2D Fourier expansion is used in a semi-sphere domain with infinite walls which contains the geometry of the original potential. Electron energies for different values of lens deformation $b/a$, lens radius $a$ and barrier height $V_o$ are calculated. In the very high confinement potential limit, the results for the infinite barrier case are recovered.

cond-mat.mes-hall↗