arXiv subjects

Tadeu Tassis

Publications and source records attributed to Tadeu Tassis.

4 recordsLinked to original sources

arXiv2025

Parametric processes in nonlinear structures with reflections: a transfer matrix method approach

The Transfer Matrix Method is a powerful numerical tool for simulating wave propagation in layered media. It has been widely applied in many fields, although its use is typically restricted to passive media. In this paper, we develop the transfer method to simulate optical nonlinear generation and give examples for processes such as difference frequency generation, spontaneous parametric down conversion, and four-wave mixing including generation of counter propagating waves. This framework enables accurate simulation of complex multilayer structures and resonant cavities, providing a versatile tool for designing nonlinear photonic devices.

physics.optics↗

arXiv2025

Parametric processes in nonlinear structures with reflections: an asymptotic-field approach

The generation of engineered quantum states of light via nonlinear processes is fundamental for quantum technologies based on photons. Although embedding nonlinear materials within resonant structures allows for the enhancement and tailoring of photon properties, accurately modeling these quantum interactions remains a challenge. In this work, we apply the asymptotic-fields formalism, an approach based on scattering theory, to describe nonlinear optical processes within a Fabry-P\'erot cavity. Unlike previous applications of this formalism, we explicitly account for reflections in the system. We derive the interaction Hamiltonian and calculate photon-pair generation rates using perturbation theory. The versatility of this model is illustrated through three examples: (i) spontaneous parametric down-conversion in an idealized cavity with flat-response mirrors; (ii) the generation of counter-propagating photon pairs in a periodically-poled material; and (iii) spontaneous four-wave mixing in a cavity built with Bragg reflectors.

quant-ph↗

arXiv2025

Realization of Trapped Ion Dynamics in the Strong-Field Regime and Non-Markovianity

We experimentally investigate trapped ion dynamics in the strong-driving regime, where the Rabi frequency (Omega) is comparable to the vibrational mode frequency (nu). In the conventional weak-driving regime (Omega << nu), the dynamics is well described by effective Hamiltonians for the carrier and motional sidebands, associated with detunings (delta = n nu (n = 0, +/- 1, ...)). In the strong-driving regime (Omega ~ nu), these interactions can no longer be treated independently. We characterize this physics through the reduced dynamics of the qubit, where non-Markovian behavior emerges as an operational probe of the spin-motion coupling. We observe a structured non-Markovian response, with well-defined maxima that follow the generalized resonance condition (delta^2 + Omega^2 = nu^2), reflecting the strong underlying spin-motion hybridization characteristic of the strong-driving regime.

quant-ph↗

arXiv2020

Some novel considerations about the collective coordinates approximation for the scattering of $ϕ^4$ kinks

The collective coordinates approximation for the kink/anti-kink scattering in the $1+1$ dimensional $ϕ^4$ model is considered and we discuss how the results found in the current literature on the topic can be improved by giving the analytical expression for the lagrangian in the space of parameters. A comprehensive discussion of the role of the collective coordinates approximation in this particular situation is given for completeness.

hep-th↗