https://repositorio.ufu.br/handle/123456789/5166 2026-06-09T16:39:55Z 2026-06-09T16:39:55Z https://repositorio.ufu.br/handle/123456789/48735 2026-06-04T06:19:21Z 2026-04-29T00:00:00Z

Title: Memorial

2026-04-29T00:00:00Z https://repositorio.ufu.br/handle/123456789/48605 2026-04-07T06:20:11Z 2026-02-28T00:00:00Z

Title: Eletrodinâmica Quântica de Cavidades na Faixa de Micro-ondas em Chips Semicondutores com Pontos Quânticos Definidos Eletrostaticamente Abstract: This work presents a theoretical and computational study of light-matter interaction in circuit quantum electrodynamics (cQED) architectures based on semiconductor quantum dots. Using the density matrix formalism and the theory of open quantum systems, we employ the Lindblad master equation to model dissipative mechanisms, including energy relaxation (T1) and decoherence (T2). The theoretical framework starts from the quantization of the electromagnetic field and the Jaynes-Cummings model within the rotating-wave approximation (RWA), and is extended to the dispersive regime via the Schrieffer-Wolff transformation, yielding effective Hamiltonians and dispersive shifts. We then perform numerical simulations to characterize coherent dynamics under microwave control and to compare the obtained results with experimental benchmarks reported in the literature, with emphasis on reproducing Rabi oscillations and Ramsey interferometry. Finally, we examine the limits of validity of the RWA at stronger coupling and demonstrate the controlled preparation of dark states (decoherence-free subspaces) in the two-qubit Tavis-Cummings model.

2026-02-28T00:00:00Z https://repositorio.ufu.br/handle/123456789/48549 2026-03-19T06:20:28Z 2026-02-24T00:00:00Z

Title: Um lugar para cada coisa e cada coisa em seu lugar: ensino, pesquisa e extensão - uma trajetória musical

2026-02-24T00:00:00Z https://repositorio.ufu.br/handle/123456789/48521 2026-03-07T06:30:42Z 2026-02-02T00:00:00Z

Title: Estudo optoestrutural de perovskitas de iodeto de césio e chumbo em vidro borossilicato: efeitos da dopagem com terras raras e nióbio Abstract: In this work, the structural and optical properties of CsPbI3 perovskites embedded in a borosilicate glass matrix, doped with rare-earth ions (Nd3+, Er3+, Sm3+, and Ho3+) and co-doped with Nb⁵⁺, were investigated. The results show that increasing the Nb5+ concentration favors its incorporation into the glass matrix and promotes the formation of the cubic perovskite phase. The addition of rare-earth ions also contributes to the stabilization of this phase, although no dominant element could be identified. Raman spectroscopy confirmed the presence of vibrational modes associated with the SNAB glass matrix and the role of Nb5+ as a network modifier. Temperature-dependent photoluminescence spectra exhibited emission bands attributed to CsPbI3, with a maximum at ~720 nm (1.72 eV) at 77 K, shifting to ~700 nm (1.78 eV) with increasing temperature, accompanied by spectral broadening and thermal quenching. Among the investigated samples, the Er3+-doped compositions are the most promising, due to the effective stabilization of the cubic phase and their potential application as optical thermometers, exhibiting a relative sensitivity of 4.3% K-1. These results demonstrate that co-doping with Nb5+ and rare-earth ions is an efficient strategy to control the structural stability and optical properties of CsPbI3 perovskites embedded in glass matrices.

2026-02-02T00:00:00Z