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1.
Nat Mater ; 21(2): 188-194, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34857910

RESUMO

The Josephson effect results from the coupling of two superconductors across a spacer such as an insulator, a normal metal or a ferromagnet to yield a phase coherent quantum state. However, in junctions with ferromagnetic spacers, very long-range Josephson effects have remained elusive. Here we demonstrate extremely long-range (micrometric) high-temperature (tens of kelvins) Josephson coupling across the half-metallic manganite La0.7Sr0.3MnO3 combined with the superconducting cuprate YBa2Cu3O7. These planar junctions, in addition to large critical currents, display the hallmarks of Josephson physics, such as critical current oscillations driven by magnetic flux quantization and quantum phase locking effects under microwave excitation (Shapiro steps). The latter display an anomalous doubling of the Josephson frequency predicted by several theories. In addition to its fundamental interest, the marriage between high-temperature, dissipationless quantum coherent transport and full spin polarization brings opportunities for the practical realization of superconducting spintronics, and opens new perspectives for quantum computing.

2.
Occup Med (Lond) ; 73(8): 512-517, 2023 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-38029440

RESUMO

BACKGROUND: In 2017, 69 108 work-related traffic injuries with medical leave were documented, constituting 12% of all occupational injuries (OI) in Spain. AIMS: The aim of this study was to describe OI within a Spanish bank company during 2017. METHODS: A cross-sectional analysis was conducted using the company's mandatory OI records, presenting data in both absolute (n) and relative (%) frequencies. The chi-square test was employed for comparisons. RESULTS: Among the company's 10 399 employees, 176 OI cases were recorded. Most were minor musculoskeletal incidents, with one severe myocardial infarction and one mild anxiety episode. Lower limb injuries were the most prevalent. Injuries of the trunk (P < 0.001), neck (P < 0.05), and upper limbs (P < 0.001) were linked to workplace factors. Approximately 62% of OI occurred outside the workplace and resulted in more extended medical leave (P < 0.01). Traffic-related injuries accounted for 39% of OI cases and caused 49% of days lost due to OI (P < 0.001).Female gender (P < 0.001) and age over 40 years (P < 0.05) were significantly associated with OI. CONCLUSIONS: In our study, musculoskeletal injuries were the most common, with a single cardiovascular event being the most severe. OI occurring outside the workplace was more frequent and led to longer medical leaves. Notably, traffic-related injuries were especially significant, exceeding official statistics 4-fold.


Assuntos
Infarto do Miocárdio , Traumatismos Ocupacionais , Humanos , Feminino , Adulto , Traumatismos Ocupacionais/epidemiologia , Traumatismos Ocupacionais/etiologia , Estudos Transversais , Local de Trabalho , Infarto do Miocárdio/complicações , Espanha/epidemiologia
3.
Phys Rev Lett ; 128(8): 082001, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35275686

RESUMO

Events containing a Z boson and a charm jet are studied for the first time in the forward region of proton-proton collisions. The data sample used corresponds to an integrated luminosity of 6 fb^{-1} collected at a center-of-mass energy of 13 TeV with the LHCb detector. In events with a Z boson and a jet, the fraction of charm jets is determined in intervals of Z-boson rapidity in the range 2.0

4.
Phys Rev Lett ; 125(26): 266802, 2020 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-33449729

RESUMO

The persistence of ferroelectricity in ultrathin layers relies critically on screening or compensation of polarization charges which otherwise destabilize the ferroelectric state. At surfaces, charged defects play a crucial role in the screening mechanism triggering novel mixed electrochemical-ferroelectric states. At interfaces, however, the coupling between ferroelectric and electrochemical states has remained unexplored. Here, we make use of the dynamic formation of the oxygen vacancy profile in the nanometer-thick barrier of a ferroelectric tunnel junction to demonstrate the interplay between electrochemical and ferroelectric degrees of freedom at an oxide interface. We fabricate ferroelectric tunnel junctions with a La_{0.7}Sr_{0.3}MnO_{3} bottom electrode and BaTiO_{3} ferroelectric barrier. We use poling strategies to promote the generation and transport of oxygen vacancies at the metallic top electrode. Generated oxygen vacancies control the stability of the ferroelectric polarization and modify its coercive fields. The ferroelectric polarization, in turn, controls the ionization of oxygen vacancies well above the limits of thermodynamic equilibrium, triggering the build up of a Schottky barrier at the interface which can be turned on and off with ferroelectric switching. This interplay between electronic and electrochemical degrees of freedom yields very large values of the electroresistance (more than 10^{6}% at low temperatures) and enables a controlled switching between clockwise and counterclockwise switching modes in the same junction (and consequently, a change of the sign of the electroresistance). The strong coupling found between electrochemical and electronic degrees of freedom sheds light on the growing debate between resistive and ferroelectric switching in ferroelectric tunnel junctions, and moreover, can be the source of novel concepts in memory devices and neuromorphic computing.

5.
Plant Cell ; 28(6): 1372-87, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26628743

RESUMO

Roots normally grow in darkness, but they may be exposed to light. After perceiving light, roots bend to escape from light (root light avoidance) and reduce their growth. How root light avoidance responses are regulated is not well understood. Here, we show that illumination induces the accumulation of flavonols in Arabidopsis thaliana roots. During root illumination, flavonols rapidly accumulate at the side closer to light in the transition zone. This accumulation promotes asymmetrical cell elongation and causes differential growth between the two sides, leading to root bending. Furthermore, roots illuminated for a long period of time accumulate high levels of flavonols. This high flavonol content decreases both auxin signaling and PLETHORA gradient as well as superoxide radical content, resulting in reduction of cell proliferation. In addition, cytokinin and hydrogen peroxide, which promote root differentiation, induce flavonol accumulation in the root transition zone. As an outcome of prolonged light exposure and flavonol accumulation, root growth is reduced and a different root developmental zonation is established. Finally, we observed that these differentiation-related pathways are required for root light avoidance. We propose that flavonols function as positional signals, integrating hormonal and reactive oxygen species pathways to regulate root growth direction and rate in response to light.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Arabidopsis/metabolismo , Flavonóis/metabolismo , Raízes de Plantas/citologia , Raízes de Plantas/metabolismo , Arabidopsis/fisiologia , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Diferenciação Celular/fisiologia , Diferenciação Celular/efeitos da radiação , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Luz , Fototropismo/genética , Fototropismo/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/fisiologia , Raízes de Plantas/efeitos da radiação , Transdução de Sinais/fisiologia , Transdução de Sinais/efeitos da radiação
6.
Phys Rev Lett ; 122(3): 037601, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30735408

RESUMO

The electronic reconstruction occurring at oxide interfaces may be the source of interesting device concepts for future oxide electronics. Among oxide devices, multiferroic tunnel junctions are being actively investigated as they offer the possibility to modulate the junction current by independently controlling the switching of the magnetization of the electrodes and of the ferroelectric polarization of the barrier. In this Letter, we show that the spin reconstruction at the interfaces of a La_{0.7}Sr_{0.3}MnO_{3}/BaTiO_{3}/La_{0.7}Sr_{0.3}MnO_{3} multiferroic tunnel junction is the origin of a spin filtering functionality that can be turned on and off by reversing the ferroelectric polarization. The ferroelectrically controlled interface spin filter enables a giant electrical modulation of the tunneling magnetoresistance between values of 10% and 1000%, which could inspire device concepts in oxides-based low dissipation spintronics.

8.
Horm Metab Res ; 48(10): 682-686, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27632150

RESUMO

The aim of the study was to investigate the role of diabetic intrauterine environment on circulating insulin, glucagon, and somatostatin levels in pregnant rats, fetuses, and offspring. Diabetes was induced in female Wistar rats by streptozotocin at birth or as adult and the animals were assigned into: control (C); mildly diabetic (MD); and severely diabetic (SD). The rats were mated and distributed into 2 subgroups: euthanasia at day 21 of pregnancy and at day 10 postpartum. Both MD and SD dams showed impaired oral glucose tolerance. SD dams had lower body weight and insulin levels compared to C and MD dams. SD fetuses presented hyperglycemia and reduction of insulin and glucagon levels compared to C and MD fetuses. SD newborns had diminished total pancreatic insulin and plasma somatostatin compared to the other groups. MD dams and fetuses had lower glucagon and somatostatin levels compared to C dams. MD offspring had maintained lower somatostatin levels to neonatal period. Diabetes causes alterations in circulating levels of pancreatic hormones in the mother and offspring.


Assuntos
Biomarcadores/sangue , Diabetes Mellitus Experimental/fisiopatologia , Glucagon/sangue , Insulina/sangue , Hormônios Pancreáticos/sangue , Somatostatina/sangue , Animais , Animais Recém-Nascidos , Feminino , Gravidez , Ratos , Ratos Wistar
9.
Pharmacopsychiatry ; 47(1): 33-6, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24127329

RESUMO

Despite progress made in the treatment of tobacco dependence, currently available treatments are effective for only a fraction of smokers. The aim of this study was to evaluate the association between the effectiveness of treatment with nicotine or bupropion in heavy smokers (n=70), and 6 candidate polymorphisms in CYP2A6, 5-HTT and HTR2A genes. Analysis revealed a significant association between "favourable" genotype combination carriers (CYP2A6 "slow metabolizer" or 5HTT L-allele or HTR2A-1438GG) and nicotine treatment outcome (OR=2.69, 95% CI=1.28-5.64). Genetic variations in CYP2A6 gene or genotypes associated with reduced synaptic serotonin activity may influence the success of smoking cessation treatment.


Assuntos
Hidrocarboneto de Aril Hidroxilases/genética , Polimorfismo Genético/genética , Receptor 5-HT2A de Serotonina/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Abandono do Hábito de Fumar , Tabagismo/genética , Tabagismo/terapia , Adulto , Bupropiona/uso terapêutico , Citocromo P-450 CYP2A6 , Inibidores da Captação de Dopamina/uso terapêutico , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Nicotina/uso terapêutico , Agonistas Nicotínicos/uso terapêutico , Farmacogenética
10.
Scand J Med Sci Sports ; 23(3): e162-7, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23317015

RESUMO

The aim of the present case-control study was to examine the association of the ACTN3 R577X genotype with elite swimming status. We compared a group of Spanish (Caucasian) elite swimmers (n = 88) with other cohorts of the same ethnic origin, i.e., nonathletic controls (n = 343) and other types of athletes who are in both end-points of the sports performance continuum, i.e., world-class power (n = 119) and endurance male athletes (n = 154). Swimmers had a lower odds ratio (OR) of having the RX genotype [1.815, 95% confidence intervals (CI): 0.899-3.664] compared with nonathletic controls, yet the association did not reach statistical significance (P = 0.096). Endurance athletes had greater OR of having the XX genotype (OR: 2.88, 95% CI: 1.162-7.135, P = 0.022), or the RX+XX genotype (OR: 1.903, 95% CI: 1.015-3.567, P = 0.045) compared with swimmers. No other association was found. In summary, we did not observe an association between the ACTN3 R577X polymorphism and elite swimmer's status, suggesting that any influence of this polymorphism is not of sufficient magnitude as to significantly influence elite swimming performance, at least in Spanish athletes.


Assuntos
Actinina/genética , Desempenho Atlético , Natação , População Branca/genética , Adolescente , Adulto , Ciclismo , Estudos de Casos e Controles , Feminino , Heterozigoto , Homozigoto , Humanos , Masculino , Polimorfismo Genético , Corrida , Espanha , Atletismo , Voleibol , Adulto Jovem
11.
Int J Sports Med ; 33(7): 521-4, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22499569

RESUMO

The NOS3-786 T/C polymorphism (rs2070744) is a candidate to explain individual variations in sports related phenotypes. We determined the genotype and allele frequency of NOS3-786 T/C in a group of 60 male professional elite soccer players. Their results were compared with those of 100 world-class endurance athletes, 53 elite power athletes, and 100 sedentary, healthy men (controls) of the same Caucasian (Spanish) origin. There were significant differences in genotype frequencies between soccer players, controls, endurance and power elite athletes (all P ≤ 0.02). These results were confirmed when we analysed allelic frequencies (all P<0.01). The likelihood of having the C allele was higher in soccer players compared with (i) controls [odds ratio (OR), 2.165, 95% confidence interval (CI): 1.362-3.441], (ii) endurance athletes (OR: 1.879, 95%CI: 1.184-2.984), and (iii) power athletes (OR: 4.032, 95%CI: 2.307-7.047). In conclusion, the -786C allele is associated with the status of being an elite soccer player, compared with non-athletic controls and also with elite endurance and power athletes. More research is needed in other groups of elite soccer players in order to replicate the results of the present study.


Assuntos
Atletas , Óxido Nítrico Sintase Tipo III/genética , Futebol/fisiologia , Adolescente , Adulto , Alelos , Frequência do Gene , Genótipo , Humanos , Masculino , Resistência Física/fisiologia , Polimorfismo Genético , Espanha , Adulto Jovem
12.
Transl Psychiatry ; 12(1): 146, 2022 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-35393390

RESUMO

Alcohol is part of the usual diet of millions of individuals worldwide. However, not all individuals who drink alcohol experience the same effects, nor will everyone develop an alcohol use disorder. Here we propose that the intestinal microbiota (IMB) helps explain the different consumption patterns of alcohol among individuals. 507 humans participated in this study and alcohol consumption and IMB composition were analyzed. On the other hand, in 80 adult male Wistar rats, behavioral tests, alcohol intoxication, fecal transplantation, administration of antibiotics and collection of fecal samples were performed. For identification and relative quantification of bacterial taxa was used the bacterial 16 S ribosomal RNA gene. In humans, we found that heavy episodic drinking is associated with a specific stool type phenotype (type 1, according to Bristol Stool Scale; p < 0.05) and with an increase in the abundance of Actinobacteria (p < 0.05). Next, using rats, we demonstrate that the transfer of IMB from alcohol-intoxicated animals causes an increase in voluntary alcohol consumption in transplant-recipient animals (p < 0.001). The relative quantification data indicate that the genus Porphyromonas could be associated with the effect on voluntary alcohol consumption. We also show that gut microbiota depletion by antibiotics administration causes a reduction in alcohol consumption (p < 0.001) and altered the relative abundance of relevant phyla such as Firmicutes, Bacteroidetes or Cyanobacteria (p < 0.05), among others. Benjamini-Hochberg false discovery rate (FDR) correction was performed for multiple comparisons. These studies reveal some of the consequences of alcohol on the IMB and provide evidence that manipulation of IMB may alter voluntary alcohol consumption.


Assuntos
Microbioma Gastrointestinal , Consumo de Bebidas Alcoólicas , Animais , Antibacterianos/farmacologia , Bactérias , Transplante de Microbiota Fecal , Masculino , Ratos , Ratos Wistar
13.
Scand J Med Sci Sports ; 21(4): 570-9, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20459474

RESUMO

The goal of our study was to discriminate potential genetic differences between humans who are in both endpoints of the sports performance continuum (i.e. world-class endurance vs power athletes). We used DNA-microarray technology that included 36 genetic variants (within 20 different genes) to compare the genetic profile obtained in two cohorts of world-class endurance (N=100) and power male athletes (N=53) of the same ethnic origin. Stepwise multivariate logistic regression showed that the rs1800795 (IL6-174 G/C), rs1208 (NAT2 K268R) and rs2070744 (NOS3-786 T/C) polymorphisms significantly predicted sport performance (model χ(2) =25.3, df=3, P-value <0.001). Receiver-operating characteristic (ROC) curve analysis showed a significant discriminating accuracy of the model, with an area under the ROC curve of 0.72 (95% confidence interval: 0.66-0.81). The contribution of the studied genetic factors to sports performance was 21.4%. In summary, although an individual's potential for excelling in endurance or power sports can be partly predicted based on specific genetic variants (many of which remain to be identified), the contribution of complex gene-gene interactions, environmental factors and epigenetic mechanisms are also important contributors to the "complex trait" of being an athletic champion. Such trait is likely not reducible to defined genetic polymorphisms.


Assuntos
Desempenho Atlético/fisiologia , Força Muscular/genética , Resistência Física/genética , Polimorfismo Genético , Adulto , Genótipo , Humanos , Masculino , Análise em Microsséries , Valor Preditivo dos Testes , Curva ROC , Análise de Regressão , Espanha , Adulto Jovem
14.
Scand J Med Sci Sports ; 21(6): e34-41, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20561285

RESUMO

We examined the association of R577X polymorphism (rs1815739) in the α-actinin-3 (ACTN3) gene with "explosive" leg muscle power performance in a group of male and female elite volleyball players (n=66, 31 men, 35 women) and in a group of non-athletic male and female young adults (n=334, 243 men, 91 women). We assessed power performance by means of the vertical squat and counter-movement jump tests. We also determined whether the genotypic frequencies of the ACTN3 R577X genotypes differed between groups. We did not observe any effect of the ACTN3 R577X polymorphism on study phenotypes in both groups, regardless of gender (all P>0.05). Genotype frequencies were similar between volleyball and control groups (P=0.095). Moreover, we did not find an association between the ACTN3 R577X polymorphism and the likelihood of being an elite volleyball player using the dominant (RR vs RX+XX) and the recessive model (RR+RX vs XX). In summary, these findings suggest that the ACTN3 R577X polymorphism does not influence explosive leg muscle power in elite volleyball players.


Assuntos
Actinina/genética , Atletas , Desempenho Atlético/fisiologia , Perna (Membro)/fisiologia , Contração Muscular/genética , Força Muscular/genética , Polimorfismo Genético , Voleibol/fisiologia , Feminino , Humanos , Masculino , Contração Muscular/fisiologia , Fibras Musculares de Contração Rápida/metabolismo , Força Muscular/fisiologia , Análise de Sequência de DNA , Espanha , Adulto Jovem
15.
Int J Sports Med ; 32(2): 151-3, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21110287

RESUMO

We aimed to replicate the original findings by Eynon et al. showing an association between the T allele of the GNB3 C825T polymorphism and elite endurance athletic status, in larger cohorts and in other ethnicities. We compared allelic and genotypic frequencies of the GNB3 C825T polymorphism among non-athletic controls (N=340), elite endurance athletes (N=174), and power athletes (N=134). The population sample included participants from 2 different ethnic/geographic backgrounds (Israel and Spain). We observed no significant differences in genotypic and allelic frequencies between countries or groups (all P>0.1). The odds ratio (OR) of being an endurance athlete if the subject had a T allele was 0.841 (95%CI: 0.638-1.110) compared to the control group and 1.047 (95% CI: 0.751-1.461) compared to the power group. Our findings support the need to corroborate genotype:phenotype associations in the field of sports genetics with the largest possible population samples, including populations of different ethnic backgrounds.


Assuntos
Atletas , Etnicidade/genética , Proteínas Heterotriméricas de Ligação ao GTP/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Desempenho Atlético , Estudos de Coortes , Feminino , Estudos de Associação Genética , Testes Genéticos , Genética Populacional , Genótipo , Humanos , Israel , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fenótipo , Reprodutibilidade dos Testes , Espanha , Adulto Jovem
16.
Enferm Intensiva ; 22(1): 13-21, 2011.
Artigo em Espanhol | MEDLINE | ID: mdl-21315638

RESUMO

INTRODUCTION: Intensive Care Units do not adapt to the social and health reality regarding the phenomenon of death and this results in a high degree of dissatisfaction among professional, relatives and patients. The special characteristics of these units give the nursing staff a main roll as carers of critical dying patients. The principal aim of this study is to know the nursing staffs' experiences and attitudes towards the phenomenon of death in the intensive care units. PARTICIPANTS AND METHOD: A descriptive qualitative study of phenomenological character was performed. Constant comparison and progressive incorporation of participants was made, using intentional sampling up to data saturation (n=16). The data collection technique used was a semi-structured in-depth interview, which were recorded and literally transcribed. The data collected was verified by the informants and analyzed according to the steps proposed by Taylor-Bogdan. RESULTS: The analysis shows 5 thematic categories: death and beliefs, emotional work, environmental factors, decision-making management of death in intensive care units and relationships with relatives. CONCLUSIONS: The management model of death in intensive care units focuses on medical intervention and overlooks the opinions of the nurses, relatives and patients. This study shows the contributions that can be provided by the nursing staff in decision making and in the care of the dying patients in these wards.


Assuntos
Atitude do Pessoal de Saúde , Unidades de Terapia Intensiva , Enfermagem , Assistência Terminal , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
Plant Sci ; 310: 110951, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34315581

RESUMO

Plants have evolved different mechanisms to increase their tolerance to aluminum (Al) toxicity and low pH in the soil. The Zn finger transcription factor SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1) plays an essential role in the adaptation of plants to Al and low pH stresses. In this work, we isolated the ScSTOP1 gene from rye (Secale cereale L.), which is located on chromosome 3RS. The ectopic expression of ScSTOP1 complements the Arabidopsis stop1 mutation in terms of root growth inhibition due to Al and pH stress, as well as phosphate starvation tolerance, suggesting that rye ScSTOP1 is a functional ortholog of AtSTOP1. A putative STOP1 binding motif was identified in the promoter of a well-known STOP1 target from rye and Arabidopsis and was later corroborated by genomic DAP-seq analyses. Coexpression analyses verified that ScSTOP1 activated the promoter of ScALMT1. We have also identified a putative phosphorylatable serine in STOP1 that is phylogenetically conserved and critical for such activation. Our data indicated that ScSTOP1 also regulated Al and pH tolerance in rye.


Assuntos
Alumínio/toxicidade , Proteínas de Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Secale/metabolismo , Proteínas de Arabidopsis/genética , Cromossomos de Plantas/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Concentração de Íons de Hidrogênio , Mutação/genética , Transportadores de Ânions Orgânicos/genética , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Secale/efeitos dos fármacos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
18.
Sci Rep ; 11(1): 20788, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34675339

RESUMO

Research on proximity effects in superconductor/ferromagnetic hybrids has most often focused on how superconducting properties are affected-and can be controlled-by the effects of the ferromagnet's exchange or magnetic fringe fields. The opposite, namely the possibility to craft, tailor and stabilize the magnetic texture in a ferromagnet by exploiting superconducting effects, has been more seldom explored. Here we show that the magnetic flux trapped in high-temperature superconducting YBa2Cu3O7-δ microstructures can be used to modify the magnetic reversal of a hard ferromagnet-a cobalt/platinum multilayer with perpendicular magnetic anisotropy-and to imprint unusual magnetic domain distributions in a controlled manner via the magnetic field history. The domain distributions imprinted in the superconducting state remain stable, in absence of an external magnetic field, even after increasing the temperature well above the superconducting critical temperature, at variance to what has been observed for soft ferromagnets with in-plane magnetic anisotropy. This opens the possibility of having non-trivial magnetic configuration textures at room temperature after being tailored below the superconducting transition temperature. The observed effects are well explained by micromagnetic simulations that demonstrate the role played by the magnetic field from the superconductor on the nucleation, propagation, and stabilization of magnetic domains.

19.
Nanoscale ; 13(40): 17125-17135, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34635906

RESUMO

A metal-insulator transition is observed in spin-orbit-coupled IrO2 thin films upon reduction of the film thickness. In the epitaxially grown samples, the critical thickness (t ∼ 1.5-2.2 nm) is found to depend on growth orientation (001), (100) or (110). Interestingly from the applied point of view, the insulating behavior is found even in polycrystalline ultrathin films. By analyzing the experimental electrical response with various theoretical models, we find good fits to the Efros-Shklovskii-VRH and the Arrhenius-type behaviors, which suggests an important role of electron correlations in determining the electrical properties of IrO2. Our magnetic measurements also point to a significant role of magnetic order. Altogether, our results would point to a mixed Slater- and Mott-type of insulator.

20.
Nat Commun ; 12(1): 3283, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34078889

RESUMO

The anomalous Hall effect (AHE) is an intriguing transport phenomenon occurring typically in ferromagnets as a consequence of broken time reversal symmetry and spin-orbit interaction. It can be caused by two microscopically distinct mechanisms, namely, by skew or side-jump scattering due to chiral features of the disorder scattering, or by an intrinsic contribution directly linked to the topological properties of the Bloch states. Here we show that the AHE can be artificially engineered in materials in which it is originally absent by combining the effects of symmetry breaking, spin orbit interaction and proximity-induced magnetism. In particular, we find a strikingly large AHE that emerges at the interface between a ferromagnetic manganite (La0.7Sr0.3MnO3) and a semimetallic iridate (SrIrO3). It is intrinsic and originates in the proximity-induced magnetism present in the narrow bands of strong spin-orbit coupling material SrIrO3, which yields values of anomalous Hall conductivity and Hall angle as high as those observed in bulk transition-metal ferromagnets. These results demonstrate the interplay between correlated electron physics and topological phenomena at interfaces between 3d ferromagnets and strong spin-orbit coupling 5d oxides and trace an exciting path towards future topological spintronics at oxide interfaces.

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