Quantum phase transitions in one-dimensional nanostructures: a comparison between DFT and DMRG methodologies.

CONTEXT: In the realm of quantum chemistry, the accurate prediction of electronic structure and properties of nanostructures remains a formidable challenge. Density functional theory (DFT) and density matrix renormalization group (DMRG) have emerged as two powerful computational methods for addressing electronic correlation effects in diverse molecular systems. We compare ground-state energies ( e 0 ), density profiles ( n ), and average entanglement entropies ( S ¯ ) in metals, insulators and at the transition from metal to insulator, in homogeneous, superlattices, and harmonically confined chains described by the fermionic one-dimensional Hubbard model. While for the homogeneous systems, there is a clear hierarchy between the deviations, D % ( S ¯ ) < D % ( e 0 ) < D ¯ % ( n ) , and all the deviations decrease with the chain size; for superlattices and harmonic confinement, the relation among the deviations is less trivial and strongly dependent on the superlattice structure and the confinement strength considered. For the superlattices, in general, increasing the number of impurities in the unit cell represents lower precision in the DFT calculations. For the confined chains, DFT performs better for metallic phases, while the highest deviations appear for the Mott and band-insulator phases. This work provides a comprehensive comparative analysis of these methodologies, shedding light on their respective strengths, limitations, and applications. METHODS: The DFT calculations were performed using the standard Kohn-Sham scheme within the BALDA approach. It integrated the numerical Bethe-Ansatz (BA) solution of the Hubbard model as the homogeneous density functional within a local-density approximation (LDA) for the exchange-correlation energy. The DMRG algorithms were implemented using the ITensor library, which is based on the matrix product states (MPS) ansatz. The calculations were performed until the energy reaches convergence of at least 10 - 8 .

Non-Hermitian linear-response theory for spin diffusion in quantum systems.

Spin transport theory of non-Hermitian quantum systems, where the non-Hermiticity led to a series of exotic phenomena when the system experiences dissipation to an environment is proposed. The goal is a better understanding of the spin diffusion in the one-dimensional non-Hermitian XXZ model which allows the transport coefficients be computed analytically. Moreover, we analyzed the electric transport in the one-dimensional non-Hermitian Hubbard model which is a very important model of electrons strongly correlated, where we have investigated the effect of non-Hermitian parameters like the imaginary hopping on AC and DC conductivities of the system. We analyzed the large U limit of this model, where such non-Hermiticity contributes with a minus sign in the virtual exchange of quasiparticles and the behavior of the ground state energy and low-lying excitations is reversed.

The cumulant Green's functions method for the Hubbard model.

We use the cumulant Green's functions method (CGFM) to study the single-band Hubbard model. The starting point of the method is to diagonalize a cluster ('seed') containingNcorrelated sites and employ the cumulants calculated from the cluster solution to obtain the full Green's functions for the lattice. All calculations are done directly; no variational or self-consistent process is needed. We benchmark the one-dimensional results for the gap, the double occupancy, and the ground-state energy as functions of the electronic correlation at half-filling and the occupation numbers as functions of the chemical potential obtained from the CGFM against the corresponding results of the thermodynamic Bethe ansatz and the quantum transfer matrix methods. The particle-hole symmetry of the density of states is fulfilled, and the gap, occupation numbers, and ground-state energy tend systematically to the known results as the cluster size increases. We include a straightforward application of the CGFM to simulate the singles occupation of an optical lattice experiment with lithium-6 atoms in an eight-site Fermi-Hubbard chain near half-filling. The method can be applied to any parameter space for one, two, or three-dimensional Hubbard Hamiltonians and extended to other strongly correlated models, like the Anderson Hamiltonian, thet - J, Kondo, and Coqblin-Schrieffer models.

Critical Current Density in d-Wave Hubbard Superconductors.

In this work, the Generalized Hubbard Model on a square lattice is applied to evaluate the electrical current density of high critical temperature d-wave superconductors with a set of Hamiltonian parameters allowing them to reach critical temperatures close to 100 K. The appropriate set of Hamiltonian parameters permits us to apply our model to real materials, finding a good quantitative fit with important macroscopic superconducting properties such as the critical superconducting temperature (Tc) and the critical current density (Jc). We propose that much as in a dispersive medium, in which the velocity of electrons can be estimated by the gradient of the dispersion relation ∇ε(k), the electron velocity is proportional to ∇E(k) in the superconducting state (where E(k)=(ε(k)-µ)2+Δ2(k) is the dispersion relation of the quasiparticles, and k is the electron wave vector). This considers the change of ε(k) with respect to the chemical potential (µ) and the formation of pairs that gives rise to an excitation energy gap Δ(k) in the electron density of states across the Fermi level. When ε(k)=µ at the Fermi surface (FS), only the term for the energy gap remains, whose magnitude reflects the strength of the pairing interaction. Under these conditions, we have found that the d-wave symmetry of the pairing interaction leads to a maximum critical current density in the vicinity of the antinodal k-space direction (π,0) of approximately 1.407236×108 A/cm2, with a much greater current density along the nodal direction (π2,π2) of 2.214702×109 A/cm2. These results allow for the establishment of a maximum limit for the critical current density that could be attained by a d-wave superconductor.

Approximating quantum thermodynamic properties using DFT.

The fabrication, utilisation, and efficiency of quantum technology devices rely on a good understanding of quantum thermodynamic properties. Many-body systems are often used as hardware for these quantum devices, but interactions between particles make the complexity of related calculations grow exponentially with the system size. Here we explore and systematically compare 'simple' and 'hybrid' approximations to the average work and entropy variation built on static density functional theory concepts. These approximations are computationally cheap and could be applied to large systems. We exemplify them considering driven one-dimensional Hubbard chains and show that, for 'simple' approximations and low to medium temperatures, it pays to consider a good estimate of the Kohn-Sham Hamiltonian to approximate the driving Hamiltonian. Our results confirm that a 'hybrid' approach, requiring a very good approximation of the initial and, for the entropy, final states of the system, provides great improvements. This approach should be particularly efficient when many-body effects are not increased by the driving Hamiltonian.

Optimization of Thurston's Core Entropy Algorithm for Polynomials with a Critical Point of Maximal Order.

This paper discusses some properties of the topological entropy systems generated by polynomials of degree d in their Hubbard tree. An optimization of Thurston's core entropy algorithm is developed for a family of polynomials of degree d.

Desempenho e características de carcaça de três genótipos comerciais de frangos de corte alimentados com diferentes dietas / Performance and carcass traits of three commercial broiler genotypes fed different diets

Este estudo teve como objetivo avaliar o desempenho e as características de carcaça de frangos de corte de três genótipos comerciais do nascimento aos 35 dias de idade. Utilizou-se um total de 2.970 pintos de três genótipos de aves comerciais (Cobb 500, Hubbard Flex e Ross 308). Os programas nutricionais foram dieta basal, dieta com 10% mais e 10% menos de aminoácidos do que a dieta basal. As aves foram distribuídas em delineamento inteiramente ao acaso, em esquema fatorial 3x3x2 (genótipo x dieta x sexo), com cinco repetições e 33 aves por unidade experimental. Conversão alimentar, ganho de peso diário, ingestão da dieta e peso corporal aos 35 dias de idade foram registrados. Duas aves de cada unidade experimental foram amostradas e abatidas aos 35 dias de idade para avaliar as seguintes características de carcaça: peso corporal no momento do abate, peso da carcaça e rendimento, e peso e rendimento dos cortes (peito, pernas e asas). Houve uma interação significativa entre o genótipo e sexo para GPD e PC35. Os machos apresentaram melhores desempenhos e características de carcaças do que as fêmeas.(AU)

This study aimed to evaluate performance and carcass traits of three commercial broiler genotypes from hatch to 35 days of age. A total of 2,970 sexed one day old chicks of three commercial broiler genotypes (Cobb 500, Hubbard Flex and Ross 308) were used. The nutritional programs were basal diet, diet with 10% more and 10% less amino acids than the basal diets. Birds were distributed in a completely randomized experimental design in a 3x3x2 (genotype x diet x sex) factorial scheme, with five replicates and 33 birds per experimental unit. Feed conversion, daily weight gain, diet intake and body weight at 35 days of age were recorded. Two birds from each experimental unit were sampled and slaughtered at 35 days of age to evaluate the following carcass traits: slaughter body weight, carcass weight and yield, and main cuts (breast, legs and wings) weight and yield. There was a significant interaction between genotype and sex for ADG and BW35. Males fed basal diets presented higher performance and carcass traits in comparison to females.(AU)

Desempenho e características de carcaça de três genótipos comerciais de frangos de corte alimentados com diferentes dietas / Performance and carcass traits of three commercial broiler genotypes fed different diets

Este estudo teve como objetivo avaliar o desempenho e as características de carcaça de frangos de corte de três genótipos comerciais do nascimento aos 35 dias de idade. Utilizou-se um total de 2.970 pintos de três genótipos de aves comerciais (Cobb 500, Hubbard Flex e Ross 308). Os programas nutricionais foram dieta basal, dieta com 10% mais e 10% menos de aminoácidos do que a dieta basal. As aves foram distribuídas em delineamento inteiramente ao acaso, em esquema fatorial 3x3x2 (genótipo x dieta x sexo), com cinco repetições e 33 aves por unidade experimental. Conversão alimentar, ganho de peso diário, ingestão da dieta e peso corporal aos 35 dias de idade foram registrados. Duas aves de cada unidade experimental foram amostradas e abatidas aos 35 dias de idade para avaliar as seguintes características de carcaça: peso corporal no momento do abate, peso da carcaça e rendimento, e peso e rendimento dos cortes (peito, pernas e asas). Houve uma interação significativa entre o genótipo e sexo para GPD e PC35. Os machos apresentaram melhores desempenhos e características de carcaças do que as fêmeas.(AU)

This study aimed to evaluate performance and carcass traits of three commercial broiler genotypes from hatch to 35 days of age. A total of 2,970 sexed one day old chicks of three commercial broiler genotypes (Cobb 500, Hubbard Flex and Ross 308) were used. The nutritional programs were basal diet, diet with 10% more and 10% less amino acids than the basal diets. Birds were distributed in a completely randomized experimental design in a 3x3x2 (genotype x diet x sex) factorial scheme, with five replicates and 33 birds per experimental unit. Feed conversion, daily weight gain, diet intake and body weight at 35 days of age were recorded. Two birds from each experimental unit were sampled and slaughtered at 35 days of age to evaluate the following carcass traits: slaughter body weight, carcass weight and yield, and main cuts (breast, legs and wings) weight and yield. There was a significant interaction between genotype and sex for ADG and BW35. Males fed basal diets presented higher performance and carcass traits in comparison to females.(AU)

IRRIGAÇÃO DO TIMO EM AVES (Gallus gallus domesticus) DA LINHAGEM HUBBARD

Estudou-se o número de lobos e as origens das artérias, que irrigaram o timo em 30 aves, Gallus gallus domesticus, da linhagem Hubbard, mediante injeção de solução aquosa de Neoprene látex 450? corada e posterior dissecação. Os resultados nos permitiram as seguintes conclusões: 1) O número de lobos tímicos para o antímero direito variou de 4 a 13, e para o antímero esquerdo e de 3 a 11; 2) Os vasos destinados ao timo originaram-se diretamente da artéria comum do nervo vago, das artérias tireóideas cranial e caudal, artéria cervical cutânea ascendente e artérias esofágicas ascendentes direita e esquerda; 3) Os lobos tímicos direitos receberam independentemente de sua origem, de 5 a 19 ramos vasculares. Quanto aos lobos tímicos esquerdos notou-se serem irrigados por 7 a 18 ramos; 4) O número de ramos penetrantes para os lobos tímicos do antímero direito variou de 8 a 25 ramos, enquanto o do antímero esquerdo de 9 a 22 ramos.

IRRIGAÇÃO DO TIMO EM AVES (Gallus gallus domesticus) DA LINHAGEM HUBBARD

Estudou-se o número de lobos e as origens das artérias, que irrigaram o timo em 30 aves, Gallus gallus domesticus, da linhagem Hubbard, mediante injeção de solução aquosa de Neoprene látex 450? corada e posterior dissecação. Os resultados nos permitiram as seguintes conclusões: 1) O número de lobos tímicos para o antímero direito variou de 4 a 13, e para o antímero esquerdo e de 3 a 11; 2) Os vasos destinados ao timo originaram-se diretamente da artéria comum do nervo vago, das artérias tireóideas cranial e caudal, artéria cervical cutânea ascendente e artérias esofágicas ascendentes direita e esquerda; 3) Os lobos tímicos direitos receberam independentemente de sua origem, de 5 a 19 ramos vasculares. Quanto aos lobos tímicos esquerdos notou-se serem irrigados por 7 a 18 ramos; 4) O número de ramos penetrantes para os lobos tímicos do antímero direito variou de 8 a 25 ramos, enquanto o do antímero esquerdo de 9 a 22 ramos.

Viscosidade do Sangue como Parâmetro de Diagnóstico da Síndrome Ascítica em Linhagens de Frangos de Corte com Diferentes Suscetibilidade

The objective of this work was to investigate the development of ascites in broilers from Hubbard and Naked-neck strains based on the change in blood viscosity. The broilers were reared up to 45 days of age at different environmental temperatures (thermoneutral or cold) and fed pelleted diets with high energy content. At 28 and 45 days, blood samples were obtained to measure the apparent blood viscosity, using a viscosimeter of concentric cylinders, and hematocrit. The results showed that at 28 days of age, some occurrence of ascites was verified in Hubbard birds living in the cold environment, but at 45 days of age all the birds reared at cold temperature had developed ascites. The Naked-neck broilers were resistant to the development of ascites at all ages and environmental temperatures. The analysis of blood apparent viscosity revealed that in birds having values similar or higher than 4 cP (centipoise) were ascitics. In conclusion, the findings of this work suggest that 4 cP of blood apparent viscosity seems to be a threshold for detecting ascites development in commercial broiler strain.

O objetivo deste trabalho foi investigar o desenvolvimento de ascites em duas linhagens diferentes de frangos de corte, Hubbard e Pescoço-pelado, através da variação da viscosidade do sangue. As aves foram criadas até 45 dias de idade em duas temperaturas ambiente diferentes (termoneutra e fria) e com dieta de ração à base de milho e farelo de soja, peletizada e de alta energia. Aos 28 e 45 dias de idade, amostras de 8 mL de sangue foram obtidas para determinação da viscosidade aparente em um viscosímetro de cilindros concêntricos da marca Brookfield, modelo LVDII+ e para determinação do hematócrito. Aos 28 dias de idade foram verificadas algumas ocorrências de ascite nas aves da linhagem Hubbard criadas à temperatura ambiente fria, e aos 45 dias de idade, todos os frangos de corte dessa linhagem criados no ambiente frio apresentaram ascite. A linhagem Pescoço-pelado foi resistente ao desenvolvimento de ascite em todas as idades e temperaturas ambiente. A análise dos resultados da viscosidade aparente do sangue indicaram que aves com valores similares ou maiores que 4 cP (centipoise) apresentaram ascite. Podemos concluir que na linhagem comercial o valor de 4 cP para a viscosidade aparente parece identificar o desenvolvimento de ascite.

Viscosidade do Sangue como Parâmetro de Diagnóstico da Síndrome Ascítica em Linhagens de Frangos de Corte com Diferentes Suscetibilidade

The objective of this work was to investigate the development of ascites in broilers from Hubbard and Naked-neck strains based on the change in blood viscosity. The broilers were reared up to 45 days of age at different environmental temperatures (thermoneutral or cold) and fed pelleted diets with high energy content. At 28 and 45 days, blood samples were obtained to measure the apparent blood viscosity, using a viscosimeter of concentric cylinders, and hematocrit. The results showed that at 28 days of age, some occurrence of ascites was verified in Hubbard birds living in the cold environment, but at 45 days of age all the birds reared at cold temperature had developed ascites. The Naked-neck broilers were resistant to the development of ascites at all ages and environmental temperatures. The analysis of blood apparent viscosity revealed that in birds having values similar or higher than 4 cP (centipoise) were ascitics. In conclusion, the findings of this work suggest that 4 cP of blood apparent viscosity seems to be a threshold for detecting ascites development in commercial broiler strain.

O objetivo deste trabalho foi investigar o desenvolvimento de ascites em duas linhagens diferentes de frangos de corte, Hubbard e Pescoço-pelado, através da variação da viscosidade do sangue. As aves foram criadas até 45 dias de idade em duas temperaturas ambiente diferentes (termoneutra e fria) e com dieta de ração à base de milho e farelo de soja, peletizada e de alta energia. Aos 28 e 45 dias de idade, amostras de 8 mL de sangue foram obtidas para determinação da viscosidade aparente em um viscosímetro de cilindros concêntricos da marca Brookfield, modelo LVDII+ e para determinação do hematócrito. Aos 28 dias de idade foram verificadas algumas ocorrências de ascite nas aves da linhagem Hubbard criadas à temperatura ambiente fria, e aos 45 dias de idade, todos os frangos de corte dessa linhagem criados no ambiente frio apresentaram ascite. A linhagem Pescoço-pelado foi resistente ao desenvolvimento de ascite em todas as idades e temperaturas ambiente. A análise dos resultados da viscosidade aparente do sangue indicaram que aves com valores similares ou maiores que 4 cP (centipoise) apresentaram ascite. Podemos concluir que na linhagem comercial o valor de 4 cP para a viscosidade aparente parece identificar o desenvolvimento de ascite.

Species of Eimeria found in reproductive hens on the North of Paraná State, Brazil / Ocorrência de Eimeria spp em galinhas reprodutoras no norte do Paraná

A survey was conducted from May to June, 1989 in Londrina, Sabáudia and Guaraci, cities in the North of Paraná State, Brazil, Faecal samples from 23 poultry houses of flocks belonging to the HUBBARD lineage were examined after centrifugal floating in saturated solution of sacarose. A solution of Bichromate Potassium 2,5% was used to identify the species, of oocysts from Eimeria spp causing esporulation. The samples even were taken from 3% of the chicken from each poultry house and the age varied from 2 to 93 weeks. 5 species were found in the following percentage: E. acervulina (32,6%), E. necatrix (16,6%), E. tenella (5r4%), E, mitis (1,8%) e E. maxima (1,8%).

O estudo foi realizado em 3 granjas de matrizes pesadas nos municípios de Londrina, Sabáudia e Guaraci, localizados no norte do Paraná, nos meses de maio e junho de 1989. As amostras de fezes frescas provenientes de 23 galpões de reprodutoras da linhagem HUBBARD foram examinadas após flutuação centrífuga em solução saturada de sacarose. Para a identificação das espécies de oocistos de Eimeria spp envolvidas, utilizou-se a solução de bicromato de potássio a 2,5% para esporulação. As amostras foram colhidas de 3% das aves de cada galpão e a faixa etária, variou de 2 a 93 semanas de idade. Foram encontrados 5 espécies com os seguintes percentuais: E. acervulina (32,6%), E. necatrix (16,6), E. tenella (5.4%), E. mitis (1,8%) e E. maxima (1,8%).

Species of Eimeria found in reproductive hens on the North of Paraná State, Brazil. / Ocorrência de Eimeria spp em galinhas reprodutoras no norte do Paraná

A survey was conducted from May to June, 1989 in Londrina, Sabáudia and Guaraci, cities in the North of Paraná State, Brazil, Faecal samples from 23 poultry houses of flocks belonging to the HUBBARD lineage were examined after centrifugal floating in saturated solution of sacarose. A solution of Bichromate Potassium 2,5% was used to identify the species, of oocysts from Eimeria spp causing esporulation. The samples even were taken from 3% of the chicken from each poultry house and the age varied from 2 to 93 weeks. 5 species were found in the following percentage: E. acervulina (32,6%), E. necatrix (16,6%), E. tenella (5r4%), E, mitis (1,8%) e E. maxima (1,8%).  

O estudo foi realizado em 3 granjas de matrizes pesadas nos municípios de Londrina, Sabáudia e Guaraci, localizados no norte do Paraná, nos meses de maio e junho de 1989. As amostras de fezes frescas provenientes de 23 galpões de reprodutoras da linhagem HUBBARD foram examinadas após flutuação centrífuga em solução saturada de sacarose. Para a identificação das espécies de oocistos de Eimeria spp envolvidas, utilizou-se a solução de bicromato de potássio a 2,5% para esporulação. As amostras foram colhidas de 3% das aves de cada galpão e a faixa etária, variou de 2 a 93 semanas de idade. Foram encontrados 5 espécies com os seguintes percentuais: E. acervulina (32,6%), E. necatrix (16,6), E. tenella (5.4%), E. mitis (1,8%) e E. maxima (1,8%).