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1.
Age Ageing ; 53(9)2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39324773

RESUMO

BACKGROUND: To explore temporal trends and determine driving factors of age-related macular degeneration (AMD) burden in older adults aged 60-89 years at global, regional and national levels from 1990 to 2019. METHODS: Prevalence and years lived with disability (YLDs) were extracted. Joinpoint regression analysis was adopted to calculate average annual percentage change and to identify the year with the most significant changes. Global trends were stratified by sex, age and sociodemographic index, and regional and national trends were explored. Decomposition analysis was conducted to determine what extent the forces of population size, age structure and epidemiologic change driving alterations of AMD burden. RESULTS: Globally, prevalence rate slightly increased whereas YLDs rate decreased. The year 2005 marked a turning point where both prevalence and YLDs started to decline. Regionally, Western Sub-Saharan Africa had the highest prevalence and YLDs rates in 2019, with East Asia experiencing the most notable rise in prevalence from 1990 to 2019. Global decomposition revealed that the increased case number was primarily driven by population growth and ageing, and epidemiological change was only detected to lessen but far from offset these impacts. CONCLUSIONS: Although there was only slight increase or even decrease in prevalence and YLDs rates of AMD in older adults, the case number still nearly doubled, which may be primarily attributed to population growth and ageing, coupled with the emerging growing pattern of prevalence rate from 2015, collectively suggesting a huge challenge in control and management of AMD.


Assuntos
Saúde Global , Degeneração Macular , Humanos , Idoso , Degeneração Macular/epidemiologia , Degeneração Macular/diagnóstico , Masculino , Idoso de 80 Anos ou mais , Feminino , Prevalência , Pessoa de Meia-Idade , Saúde Global/estatística & dados numéricos , Fatores Etários , Fatores de Risco , Efeitos Psicossociais da Doença , Fatores de Tempo
2.
J Control Release ; 372: 551-570, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38914206

RESUMO

Uveitis comprises a cluster of intraocular inflammatory disorders characterized by uncontrolled autoimmune responses and excessive oxidative stress leading to vision loss worldwide. In the present study, curcumin (CUR) was conjugated with polyvinylpyrrolidone (PVP) to form PVP-CUR nanoparticles with significantly elevated solubility and outstanding multiple radical scavenging abilities. In vitro studies revealed that PVP-CUR nanoparticles markedly mitigated oxidative stress and reduced apoptosis in a H2O2-induced human retinal pigment epithelial cell line (ARPE-19) and promoted phenotypic polarization from M1 to M2 in an LPS-induced human microglial cell line (HMC3). Further in vivo studies demonstrated the prominent therapeutic effects of PVP-CUR nanoparticles on experimental autoimmune uveitis (EAU), which relieved clinical and pathological progression, improved perfusion and tomographic manifestations of retinal vessels, and reduced blood-retinal barrier (BRB) leakage; these effects may be mediated by mitigating oxidative stress and attenuating macrophage/microglia-elicited inflammation. Notably, treatment with PVP-CUR nanoparticles was shown to regulate metabolite alterations in EAU rats, providing novel insights into the underlying mechanisms involved. Additionally, the PVP-CUR nanoparticles showed great biocompatibility in vivo. In summary, our study revealed that PVP-CUR nanoparticles may serve as effective and safe nanodrugs for treating uveitis and other oxidative stress- and inflammation-related diseases.


Assuntos
Doenças Autoimunes , Curcumina , Nanopartículas , Estresse Oxidativo , Povidona , Uveíte , Animais , Curcumina/administração & dosagem , Curcumina/farmacologia , Curcumina/química , Curcumina/uso terapêutico , Uveíte/tratamento farmacológico , Uveíte/imunologia , Uveíte/metabolismo , Povidona/química , Povidona/administração & dosagem , Nanopartículas/administração & dosagem , Nanopartículas/química , Humanos , Doenças Autoimunes/tratamento farmacológico , Linhagem Celular , Estresse Oxidativo/efeitos dos fármacos , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/metabolismo , Ratos , Feminino , Ratos Endogâmicos Lew , Barreira Hematorretiniana/efeitos dos fármacos , Barreira Hematorretiniana/metabolismo , Masculino
3.
Phys Rev Lett ; 131(21): 210603, 2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38072603

RESUMO

Fault-tolerant quantum computing based on surface code has emerged as an attractive candidate for practical large-scale quantum computers to achieve robust noise resistance. To achieve universality, magic states preparation is a commonly approach for introducing non-Clifford gates. Here, we present a hardware-efficient and scalable protocol for arbitrary logical state preparation for the rotated surface code, and further experimentally implement it on the Zuchongzhi 2.1 superconducting quantum processor. An average of 0.8983±0.0002 logical fidelity at different logical states with distance three is achieved, taking into account both state preparation and measurement errors. In particular, the logical magic states |A^{π/4}⟩_{L}, |H⟩_{L}, and |T⟩_{L} are prepared nondestructively with logical fidelities of 0.8771±0.0009, 0.9090±0.0009, and 0.8890±0.0010, respectively, which are higher than the state distillation protocol threshold, 0.859 (for H-type magic state) and 0.827 (for T-type magic state). Our work provides a viable and efficient avenue for generating high-fidelity raw logical magic states, which is essential for realizing non-Clifford logical gates in the surface code.

4.
Nature ; 619(7971): 738-742, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37438533

RESUMO

Scalable generation of genuine multipartite entanglement with an increasing number of qubits is important for both fundamental interest and practical use in quantum-information technologies1,2. On the one hand, multipartite entanglement shows a strong contradiction between the prediction of quantum mechanics and local realization and can be used for the study of quantum-to-classical transition3,4. On the other hand, realizing large-scale entanglement is a benchmark for the quality and controllability of the quantum system and is essential for realizing universal quantum computing5-8. However, scalable generation of genuine multipartite entanglement on a state-of-the-art quantum device can be challenging, requiring accurate quantum gates and efficient verification protocols. Here we show a scalable approach for preparing and verifying intermediate-scale genuine entanglement on a 66-qubit superconducting quantum processor. We used high-fidelity parallel quantum gates and optimized the fidelitites of parallel single- and two-qubit gates to be 99.91% and 99.05%, respectively. With efficient randomized fidelity estimation9, we realized 51-qubit one-dimensional and 30-qubit two-dimensional cluster states and achieved fidelities of 0.637 ± 0.030 and 0.671 ± 0.006, respectively. On the basis of high-fidelity cluster states, we further show a proof-of-principle realization of measurement-based variational quantum eigensolver10 for perturbed planar codes. Our work provides a feasible approach for preparing and verifying entanglement with a few hundred qubits, enabling medium-scale quantum computing with superconducting quantum systems.

5.
Environ Res ; 231(Pt 1): 116116, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37182831

RESUMO

Autoimmune eye diseases (AEDs), a collection of autoimmune inflammatory ocular conditions resulting from the dysregulation of immune system at the ocular level, can target both intraocular and periorbital structures leading to severe visual deficit and blindness globally. The roles of air pollution and meteorological factors in the initiation and progression of AEDs have been increasingly attractive, among which the systemic and local mechanisms are both involved in. Exposure to excessive air pollution and extreme meteorological conditions including PM2.5/PM0.1, environmental tobacco smoke, insufficient sunshine, and high temperature, etc., can disturb Th17/Treg balance, regulate macrophage polarization, activate neutrophils, induce systemic inflammation and oxidative stress, decrease retinal blood flow, promote tissue fibrosis, activate sympathetic nervous system, adversely affect nutrients synthetization, as well as induce heat stress, therefore may together deteriorate AEDs. The crosstalk among inflammation, oxidative stress and dysregulated immune system appeared to be prominent. In the present review, we will concern and summarize the potential mechanisms underlying linkages of air pollution and meteorological factors to ocular autoimmune and inflammatory responses. Moreover, we concentrate on the specific roles of air pollutants and meteorological factors in several major AEDs including uveitis, Graves' ophthalmopathy (GO), ocular allergic disease (OAD), glaucoma, diabetic retinopathy (DR), etc.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Doenças Autoimunes , Oftalmopatias , Humanos , Poluição do Ar/efeitos adversos , Poluentes Atmosféricos/toxicidade , Poluentes Atmosféricos/análise , Conceitos Meteorológicos , Doenças Autoimunes/induzido quimicamente , Doenças Autoimunes/epidemiologia , Inflamação/induzido quimicamente , Inflamação/epidemiologia , Material Particulado/toxicidade , China
6.
Sci Bull (Beijing) ; 68(9): 906-912, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37085397

RESUMO

Classifying many-body quantum states with distinct properties and phases of matter is one of the most fundamental tasks in quantum many-body physics. However, due to the exponential complexity that emerges from the enormous numbers of interacting particles, classifying large-scale quantum states has been extremely challenging for classical approaches. Here, we propose a new approach called quantum neuronal sensing. Utilizing a 61-qubit superconducting quantum processor, we show that our scheme can efficiently classify two different types of many-body phenomena: namely the ergodic and localized phases of matter. Our quantum neuronal sensing process allows us to extract the necessary information coming from the statistical characteristics of the eigenspectrum to distinguish these phases of matter by measuring only one qubit and offers better phase resolution than conventional methods, such as measuring the imbalance. Our work demonstrates the feasibility and scalability of quantum neuronal sensing for near-term quantum processors and opens new avenues for exploring quantum many-body phenomena in larger-scale systems.

7.
Autoimmun Rev ; 22(6): 103326, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36958621

RESUMO

AIM: To describe burden, and to explore cross-country inequalities across sociodemographic development levels for four autoimmune diseases (ADs) including rheumatoid arthritis (RA), inflammatory bowel disease (IBD), multiple sclerosis (MS) and psoriasis (PS). METHODS: The estimates and their 95% uncertainty interval (UI) for disability-adjusted life-years (DALYs) of RA, IBD, MS and PS were extracted from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. Age-standardized DALYs rate (ASDR) across 204 countries, as well as age and sex distribution of global DALYs rate of these four ADs were illustrated. Slope index of inequality and concentration index, which are two standard metrics of absolute and relative gradient inequality recommended by World Health Organization (WHO), were utilized to quantify the distributive inequalities in the burden of ADs. RESULTS: In 2019, the ASDR of RA, IBD, MS and PS varied remarkably across 204 countries, with different age and sex distribution of global DALYs rate. The slope index of inequality changed from 26.7 (95% CI: 20.7 to 32.8) in 1990 to 40.3 (95% CI: 31.9 to 48.7) in 2019 for RA, from 17.1 (95% CI: 12.4 to 21.7) in 1990 to 25.2 (95% CI: 20.1 to 30.2) in 2019 for IBD, from 19.3 (95% CI: 15.2 to 23.4) in 1990 to 28.9 (95% CI: 24.2 to 33.5) in 2019 for MS, from 42.3 (95% CI: 33.1 to 51.6) in 1990 to 40.2 (95% CI: 32.5 to 48.0) in 2019 for PS. Moreover, the concentration index showed 20.4 (95% CI: 18.9 to 22.0) in 1990 and 18.2 (95% CI: 16.7 to 19.6) in 2019 for RA, 25.0 (95% CI: 23.0 to 27.1) in 1990 and 33.5 (95% CI: 31.6 to 35.5) in 2019 for IBD, 46.7 (95% CI: 44.0 to 49.3) in 1990 and 41.8 (95% CI: 39.6 to 44.1) in 2019 for MS, 31.7 (95% CI: 29.0 to 34.4) in 1990 and 32.6 (95% CI: 29.9 to 35.2) in 2019 for PS. CONCLUSIONS: There is a strong heterogeneity in ASDR across all countries, as well as in age and sex distribution of global DALYs rate for four ADs including RA, IBD, MS and PS. Countries with higher sociodemographic development levels shouldered disproportionately higher burden of ADs, and the magnitude of this sociodemographic development level-related inequalities exacerbated over time.


Assuntos
Artrite Reumatoide , Esclerose Múltipla , Humanos , Expectativa de Vida , Anos de Vida Ajustados por Qualidade de Vida , Carga Global da Doença , Fatores de Risco , Artrite Reumatoide/epidemiologia , Esclerose Múltipla/epidemiologia , Saúde Global
8.
Pest Manag Sci ; 79(8): 2944-2950, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36966487

RESUMO

BACKGROUND: The German cockroach, Blattella germanica, is a ubiquitous and medically significant urban pest. The ongoing development of insecticide resistance in global populations of B. germanica has complicated control efforts and created a need for improved tools. We previously reported that disruption of the gut microbiota by oral administration of the antimicrobial doxycycline reduced resistance in an indoxacarb resistant field strain and also delayed nymphal development and reduced adult fecundity. However, the application of doxycycline for cockroach control in the field is impractical. Here, we sought to determine whether two metal nanoparticles with known antimicrobial properties, copper (Cu) and zinc oxide (ZnO), have similar effects to doxycycline on the physiology of B. germanica and could provide more practical alternatives for control. RESULTS: We found that dietary exposure to 0.1% Cu nanoparticles, but not ZnO, significantly delays the development of nymphs into adults. However, neither of the nanoparticles altered the fecundity of females, and ZnO surprisingly increased resistance to indoxacarb in a resistant field strain, in contrast to doxycycline. Semi-quantitative polymerase chain reaction (qPCR) further revealed that prolonged dietary exposure (14 days) to Cu or ZnO nanoparticles at the low concentration readily consumed by cockroaches (0.1%) does not reduce the load of the bacterial microbiota, suggesting alternative mechanisms behind their observed effects. CONCLUSIONS: Together, our results indicate that ingestion of Cu nanoparticles can impact German cockroach development through an undetermined mechanism that does not involve reducing the overall load of the bacterial microbiota. Therefore, Cu may have some applications in cockroach control as a result of this activity but antagonistic effects on insecticide resistance should be considered when evaluating the potential of nanoparticles for cockroach control. © 2023 Society of Chemical Industry.


Assuntos
Blattellidae , Baratas , Inseticidas , Nanopartículas , Óxido de Zinco , Animais , Feminino , Inseticidas/farmacologia , Cobre/farmacologia , Óxido de Zinco/farmacologia , Doxiciclina/farmacologia , Carga Bacteriana , Resistência a Inseticidas
9.
Sci Bull (Beijing) ; 67(3): 240-245, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36546072

RESUMO

To ensure a long-term quantum computational advantage, the quantum hardware should be upgraded to withstand the competition of continuously improved classical algorithms and hardwares. Here, we demonstrate a superconducting quantum computing systems Zuchongzhi 2.1, which has 66 qubits in a two-dimensional array in a tunable coupler architecture. The readout fidelity of Zuchongzhi 2.1 is considerably improved to an average of 97.74%. The more powerful quantum processor enables us to achieve larger-scale random quantum circuit sampling, with a system scale of up to 60 qubits and 24 cycles, and fidelity of FXEB=(3.66±0.345)×10-4. The achieved sampling task is about 6 orders of magnitude more difficult than that of Sycamore [Nature 574, 505 (2019)] in the classic simulation, and 3 orders of magnitude more difficult than the sampling task on Zuchongzhi 2.0 [arXiv:2106.14734 (2021)]. The time consumption of classically simulating random circuit sampling experiment using state-of-the-art classical algorithm and supercomputer is extended to tens of thousands of years (about 4.8×104 years), while Zuchongzhi 2.1 only takes about 4.2 h, thereby significantly enhancing the quantum computational advantage.

10.
J Inflamm Res ; 15: 6293-6306, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36408328

RESUMO

Introduction: Atherosclerosis (AS) is the underlying cause of cardiovascular events. Endothelial cell mitochondrial damage and pyroptosis are important factors contributing to AS. Changes in internal mitochondrial conformation and increase in reactive oxygen species (ROS) lead to the disruption of mitochondrial energy metabolism, activation of the NLRP3 inflammasome and pyroptosis, which in turn affect atherogenesis by impairing endothelial function. AMPK is a core player in the regulation of cellular metabolism, not only by regulating mitochondrial homeostasis but also by regulating cellular inflammatory responses. Sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of tanshinone IIA, has significant antioxidant and anti-inflammatory effects, and roles in cardiovascular protection. Purpose: In this study, we investigated whether STS plays a protective role in AS by regulating endothelial cell mitochondrial function and pyroptosis through an AMPK-dependent mitochondrial pathway. Methods and Results: Male ApoE-/- mice and HUVECs were used for the experiments. We found that STS treatment largely abrogated the upregulation of key proteins in aortic vessel wall plaques and typical pyroptosis signaling in ApoE-/- mice fed a western diet, consequently enhancing pAMPK expression, plaque stabilization, and anti-inflammatory responses. Consistently, STS pretreatment inhibited cholesterol crystallization (CC) -induced cell pyroptosis and activated pAMPK expression. In vitro, using HUVECs, we further found that STS treatment ameliorated mitochondrial ROS caused by CC, as evidenced by the finding that STS inhibited mitochondrial damage caused by CC. The improvement of endothelial cell mitochondrial function by STS is blocked by dorsomorphin (AMPK inhibitor). Consistently, the blockade of endothelial cell pyroptosis by STS is disrupted by dorsomorphin. Conclusion: Our results suggest that STS enhances maintenance of mitochondrial homeostasis and inhibits mitochondrial ROS overproduction via AMPK, thereby improving endothelial cell pyroptosis during AS.

11.
Phys Rev Lett ; 129(3): 030501, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35905349

RESUMO

Quantum error correction is a critical technique for transitioning from noisy intermediate-scale quantum devices to fully fledged quantum computers. The surface code, which has a high threshold error rate, is the leading quantum error correction code for two-dimensional grid architecture. So far, the repeated error correction capability of the surface code has not been realized experimentally. Here, we experimentally implement an error-correcting surface code, the distance-three surface code which consists of 17 qubits, on the Zuchongzhi 2.1 superconducting quantum processor. By executing several consecutive error correction cycles, the logical error can be significantly reduced after applying corrections, achieving the repeated error correction of surface code for the first time. This experiment represents a fully functional instance of an error-correcting surface code, providing a key step on the path towards scalable fault-tolerant quantum computing.

12.
Phys Rev Lett ; 128(16): 160502, 2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35522497

RESUMO

Understanding various phenomena in nonequilibrium dynamics of closed quantum many-body systems, such as quantum thermalization, information scrambling, and nonergodic dynamics, is crucial for modern physics. Using a ladder-type superconducting quantum processor, we perform analog quantum simulations of both the XX-ladder model and the one-dimensional XX model. By measuring the dynamics of local observables, entanglement entropy, and tripartite mutual information, we signal quantum thermalization and information scrambling in the XX ladder. In contrast, we show that the XX chain, as free fermions on a one-dimensional lattice, fails to thermalize to the Gibbs ensemble, and local information does not scramble in the integrable channel. Our experiments reveal ergodicity and scrambling in the controllable qubit ladder, and open the door to further investigations on the thermodynamics and chaos in quantum many-body systems.

13.
Natl Sci Rev ; 9(1): nwab011, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35070323

RESUMO

Quantum error correction is an essential ingredient for universal quantum computing. Despite tremendous experimental efforts in the study of quantum error correction, to date, there has been no demonstration in the realisation of universal quantum error-correcting code, with the subsequent verification of all key features including the identification of an arbitrary physical error, the capability for transversal manipulation of the logical state and state decoding. To address this challenge, we experimentally realise the [5, 1, 3] code, the so-called smallest perfect code that permits corrections of generic single-qubit errors. In the experiment, having optimised the encoding circuit, we employ an array of superconducting qubits to realise the [5, 1, 3] code for several typical logical states including the magic state, an indispensable resource for realising non-Clifford gates. The encoded states are prepared with an average fidelity of [Formula: see text] while with a high fidelity of [Formula: see text] in the code space. Then, the arbitrary single-qubit errors introduced manually are identified by measuring the stabilisers. We further implement logical Pauli operations with a fidelity of [Formula: see text] within the code space. Finally, we realise the decoding circuit and recover the input state with an overall fidelity of [Formula: see text], in total with 92 gates. Our work demonstrates each key aspect of the [5, 1, 3] code and verifies the viability of experimental realisation of quantum error-correcting codes with superconducting qubits.

14.
Chinese Journal of Cardiology ; (12): 1169-1176, 2022.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-969723

RESUMO

Objective: To estimate the prevalence, awareness, treatment and control rate of hypertension among young and middle-aged population in China. Methods: The analysis was based on the results of 2012-2015 China Hypertension Survey, which was a cross-sectional stratified multistage random sampling survey. A total of 229 593 subjects were included in the final analysis. The data including sex, age, living in urban and rural areas, prevalence of hypertension, history of stroke, family history of coronary heart disease and drinking, physical examination, heart rate were collected. Hypertension was defined as mean systolic blood pressure (SBP) ≥140 mmHg (1 mmHg=0.133 kPa), and (or) diastolic blood pressure (DBP) ≥90 mmHg, and (or) self-report a history of hypertension, and (or) use of antihypertensive medicine within 2 weeks before survey. Prehypertension was defined as SBP between 120-139 mmHg, and (or) DBP between 80-89 mmHg. Control of hypertension was considered for hypertensive individuals with SBP<140 mmHg and DBP<90 mmHg. The prevalence of prehypertension, hypertension, awareness, treatment, control rate were calculated, and the control rate among those with antihypertensive medication was also calculated. Results: The prevalence of prehypertension and hypertension was 43.8% (95%CI: 42.3%-45.4%), and 22.1% (95%CI: 20.8%-23.3%), respectively. The prevalence of prehypertension and hypertension was significantly higher among male than female across different age groups. The awareness, treatment, control rate of hypertension and control rate among treated hypertensive participants were 43.8%, 33.2%, 16.7%, and 40.2%, respectively. The prevalence was higher, and the control rate was lower among individuals with higher heart rate. Conclusion: The prevalence of prehypertension and hypertension among young and middle-aged population is high, the awareness, treatment and control rate need to be further improved in this population. The prevention and treatment of hypertension should be strengthened in the future to improve the control rate of hypertension in China.


Assuntos
Pessoa de Meia-Idade , Masculino , Feminino , Humanos , Anti-Hipertensivos/uso terapêutico , Pré-Hipertensão/epidemiologia , Prevalência , Estudos Transversais , Hipertensão/tratamento farmacológico , Pressão Sanguínea , China/epidemiologia
15.
Phys Rev Lett ; 127(18): 180501, 2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34767433

RESUMO

Scaling up to a large number of qubits with high-precision control is essential in the demonstrations of quantum computational advantage to exponentially outpace the classical hardware and algorithmic improvements. Here, we develop a two-dimensional programmable superconducting quantum processor, Zuchongzhi, which is composed of 66 functional qubits in a tunable coupling architecture. To characterize the performance of the whole system, we perform random quantum circuits sampling for benchmarking, up to a system size of 56 qubits and 20 cycles. The computational cost of the classical simulation of this task is estimated to be 2-3 orders of magnitude higher than the previous work on 53-qubit Sycamore processor [Nature 574, 505 (2019)NATUAS0028-083610.1038/s41586-019-1666-5. We estimate that the sampling task finished by Zuchongzhi in about 1.2 h will take the most powerful supercomputer at least 8 yr. Our work establishes an unambiguous quantum computational advantage that is infeasible for classical computation in a reasonable amount of time. The high-precision and programmable quantum computing platform opens a new door to explore novel many-body phenomena and implement complex quantum algorithms.

16.
Phys Rev Lett ; 127(2): 020602, 2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34296924

RESUMO

We experimentally study the ergodic dynamics of a 1D array of 12 superconducting qubits with a transverse field, and identify the regimes of strong and weak thermalization with different initial states. We observe convergence of the local observable to its thermal expectation value in the strong-thermalizaion regime. For weak thermalization, the dynamics of local observable exhibits an oscillation around the thermal value, which can only be attained by the time average. We also demonstrate that the entanglement entropy and concurrence can characterize the regimes of strong and weak thermalization. Our work provides an essential step toward a generic understanding of thermalization in quantum systems.

17.
Science ; 372(6545): 948-952, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-33958483

RESUMO

Quantum walks are the quantum mechanical analog of classical random walks and an extremely powerful tool in quantum simulations, quantum search algorithms, and even for universal quantum computing. In our work, we have designed and fabricated an 8-by-8 two-dimensional square superconducting qubit array composed of 62 functional qubits. We used this device to demonstrate high-fidelity single- and two-particle quantum walks. Furthermore, with the high programmability of the quantum processor, we implemented a Mach-Zehnder interferometer where the quantum walker coherently traverses in two paths before interfering and exiting. By tuning the disorders on the evolution paths, we observed interference fringes with single and double walkers. Our work is a milestone in the field, bringing future larger-scale quantum applications closer to realization for noisy intermediate-scale quantum processors.

18.
Phys Rev Lett ; 125(17): 170503, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33156665

RESUMO

We report the analog simulation of an ergodic-localized junction by using an array of 12 coupled superconducting qubits. To perform the simulation, we fabricated a superconducting quantum processor that is divided into two domains: one is a driven domain representing an ergodic system, while the second is localized under the effect of disorder. Because of the overlap between localized and delocalized states, for a small disorder there is a proximity effect and localization is destroyed. To experimentally investigate this, we prepare a microwave excitation in the driven domain and explore how deep it can penetrate the disordered region by probing its dynamics. Furthermore, we perform an ensemble average over 50 realizations of disorder, which clearly shows the proximity effect. Our work opens a new avenue to build quantum simulators of driven-disordered systems with applications in condensed matter physics and material science.

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