arXiv subjects

Rui E. F. Silva

Publications and source records attributed to Rui E. F. Silva.

21 records · Page 2Linked to original sources

arXiv2022

Light-wave coherent control of the insulator-to-metal transition in a strongly correlated material

The use of intense tailored light fields is the perfect tool to achieve ultrafast control of electronic properties in quantum materials. Among them, Mott insulators are materials in which strong electron-electron interactions drive the material into an insulating phase. When shinning a Mott insulator with a strong laser pulse, the electric field may induce the creation of doublon-hole pairs, triggering an insulator-to-metal phase transition. In this work, we take advantage of the threshold character of this insulator-to-metal transition and we propose a pump-probe scheme that consists of a mid-infrared laser pulse and a train of short pulses separated by half-period of the mid-infrared with alternating phases. By varying the time-delay between the two pulses and the internal carrier envelope phase of the short pulses, we achieve control of the phase transition, which leaves its fingerprint at its high harmonic spectrum.

cond-mat.str-el↗

arXiv2022

Permutational symmetry for identical multi-level systems: a second quantized approach

We develop a framework that provides a straightforward approach to fully exploit the permutational symmetry of identical multi-level systems. By taking into account the permutational symmetry, we outline a simple scheme that allows to map the dynamics of $N$ identical $d$-level systems to the dynamics of $d$ bosonic modes with $N$ particles, achieving an exponential reduction on the dimensionality of the problem in a simple and straightforward way. In particular, we consider the Lindblad dynamics of several identical multi-level systems interacting with a common subsystem under the action of collective dissipation terms.

quant-ph↗

arXiv2021

Deep neural networks for high harmonic spectroscopy in solids

Neural networks are a prominent tool for identifying and modeling complex patterns, which are otherwise hard to detect and analyze. While machine learning and neural networks have been finding applications across many areas of science and technology, their use in decoding ultrafast dynamics of quantum systems driven by strong laser fields has been limited so far. Here we use deep neural networks to analyze simulated noisy spectra of highly nonlinear optical response of a 2-dimensional gapped graphene crystal to intense few-cycle laser pulses. We show that a computationally simple 1-dimensional system provides a useful "nursery school" for our neural network, allowing it to be easily retrained to treat more complex systems, recovering the band structure and spectral phases of the incident few-cycle pulse with high accuracy, in spite of significant amplitude noise and phase jitter. Our results both offer a new tool for attosecond spectroscopy of quantum dynamics in solids and also open a route to developing all-solid-state devices for complete characterization of few-cycle pulses, including their nonlinear chirp and the carrier envelope phase.

physics.comp-ph↗