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1.
J Acoust Soc Am ; 156(3): 1920-1928, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39311605

RESUMO

Unlike acoustic metasurfaces that rely solely on phase gradients, acoustic metagratings (AMs) operate based on both phase gradients and grating diffraction, thus further extending the generalized Snell's law (GSL). In particular, AMs can achieve reversal of refraction and reflection based on the parity of the number of wave propagations inside the AMs. So far, discussions of this GSL extension have largely been applied to one-dimensional periodic AMs, while the designs of two-dimensional (2D) periodic AMs and their performance in three-dimensional (3D) space have been quite limited. Here, we study the GSL extension in 3D space and experimentally demonstrate a series of functional 2D periodic AMs. The designed AMs can achieve sound refraction/reflection under any incidence angle in 3D space, without restrictions to certain critical ranges; adjusting incident angles only enables the reversal of refraction and reflection. Additionally, we demonstrate two types of dual-layer sound lenses based on two AMs, whose reversal of refraction and reflection can be realized by simply attaching or separating the two AMs. Our work paves the way to complex 3D wavefront manipulation of AMs, which may find potential use in practical acoustic devices.

2.
Phys Rev Lett ; 133(11): 113801, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39331984

RESUMO

The past decades have witnessed the rapid development of metamaterials and metasurfaces. However, loss is still a challenging problem limiting numerous practical applications, including long-range wireless communications, superscattering, and non-Hermitian physics. Recently, great effort has been made to minimize the loss, however, they are too complicated for practical implementation and still restricted by the theoretical limit. Here, we propose and experimentally realize a tunable gain metasurface induced by negative conductivity, with deep theoretical analysis from scattering theory and equivalent circuits. In the experiment, we create metasurface samples embedded with tunable negative (or positive) conductivity to achieve adjustable gain (or loss). By varying the control bias voltages, the metasurfaces can reflect incident waves with additional controllable gain. Interestingly, we find the gain metasurfaces inherently pose nonlinearities, which are beneficial for nonlinear optics and microwave applications, particularly for the nonlinear activation of wave-based neural networks.

4.
Transplant Rev (Orlando) ; 38(4): 100878, 2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39260119

RESUMO

BACKGROUNDS: Tacrolimus is a cornerstone of posttransplantation immunosuppressive regimens. Despite routine monitoring, the efficacy of its trough concentrations in reflecting drug concentration fluctuations is limited. Intrapatient variability (IPV) emerges as a novel monitoring marker for predicting clinical outcomes. However, understanding the factors affecting IPV and assessing interventions to address it remain enigmatic, posing a conundrum in clinical management. OBJECTIVES: This systematic review aimed to investigate a spectrum of factors affecting IPV and assess the effect of strategic interventions, thereby charting a course for enhanced clinical stewardship. METHODS: We electronically searched of PubMed, Embase, and the Cochrane Library databases for studies investigating factors and interventions affecting IPV up to October 2023. Two reviewers independently screened literature, extracted data, and assessed quality, using RevMan 5.4.1 software for meta-analysis. RESULTS: A total of 15 randomized controlled trials (RCTs), 34 cohort studies, and 20 self-controlled studies were included. The results indicated that IPV was significantly higher in cytochrome P450 3A5 (CYP3A5) expressers, nonadherent patients, patients taking proton pump inhibitors or statins, and Black or African American recipients, whereas recipients consuming extended-release formulation exhibited lower IPV. Additionally, the participation of pharmacists had a positive effect on improving IPV. CONCLUSIONS: Factors affecting IPV encompassed genotype, formulation, adherence, drug combinations, and ethnicity, with each factor exerting varying degrees of effect. Identifying these factors was crucial for developing targeted intervention strategies. While the participation of pharmacists held a promise in improving IPV, further investigation of interventions such as mobile technology, educational measures to enhance adherence, and personalized dosing regimens was warranted.

5.
Adv Sci (Weinh) ; : e2406089, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39222373

RESUMO

Chiral light emission plays a key role in sensing, tomography, quantum communication, among others. Whereas, achieving highly pure, tunable chirality emission across a broad spectrum currently presents significant challenges. Free-electron radiation emerges as a promising solution to surpass these barriers, especially in hard-to-reach regimes. Here, chiral free-electron radiation is presented by exploiting the spin-momentum locking (SML) property of spoof surface plasmons (SSPs). When the phase velocity of free electrons matches that of the SSPs, the SSPs can be excited. By implementing wavenumber compensation through perturbations, the confined SSPs are transformed into free-space free-electron radiation. Owing to the law of angular momentum conservation, this process converts the transverse spin angular momentum of SSPs into the longitudinal spin angular momentum of free-electron radiation during the process, producing pure, tunable, and chiral free-electron radiation across a broad spectrum. This method achieves an optimal degree of circular polarization approaching -1. The innovative methodology can be adapted to SML-enabled guided states or silicon photonics platforms, offering new avenues for achieving chiral emission.

6.
Opt Lett ; 49(15): 4238-4241, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39090903

RESUMO

Exotic dipolar radiation with zero light emission in one direction but maximal light emission in the opposite direction was envisioned by Huygens in 1690, and it could emerge in vacuum if the ratio between the source's electric and magnetic dipole moments fulfills the Kerker condition as revealed by Kerker in 1983. Due to its intricate connection with both the Huygens principle and Kerker condition, this radiation phenomenon is suggested to be termed as dipolar Huygens-Kerker radiation, and at this moment, the ratio is termed as the Huygens-Kerker ratio. However, the dipolar Huygens-Kerker radiation remains underexplored in non-vacuum matters, inside which the source locates, especially for surface waves. Here we find that the dipolar Huygens-Kerker radiation of surface waves in principle could occur in non-vacuum matters and is essentially featured with the same normalized radiation pattern, which is closely related to the inclination factor that appears in the Fresnel-Kirchhoff diffraction theory. Moreover, the corresponding Huygens-Kerker ratio is intrinsically determined by the phase velocity of excited surface waves. To be specific, the Huygens-Kerker ratio is proportional to the phase velocity for transverse-magnetic surface waves but becomes inversely proportional to the phase velocity for transverse-electric surface waves.

7.
Adv Sci (Weinh) ; 11(33): e2308807, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38946621

RESUMO

A long-held tenet in computer science asserts that the training of deep learning is analogous to an alchemical furnace, and its "black box" signature brings forth inexplicability. For electromagnetic metasurfaces, the related intelligent applications also get stuck into such a dilemma. Although the past 5 years have witnessed a proliferation of deep learning-based works across complex photonic scenarios, they neglect the already existing but untapped physical laws. Here, the intrinsic correlation between the real and imaginary parts of the spectra are revealed using Kramers-Kronig relations, which is then mimicked by bidirectional information flow in neural network space. Such consideration harnesses the missing spectral connection to extract crucial features effectively. The bidirectional recurrent neural network is benchmarked in metasurface inverse design and compare it with a fully-connected neural network, unidirectional recurrent neural network, and attention-based transformer. Beyond the improved accuracy, the study examines the intermediate information products and physically explains why different network structures yield different performances. The work offers explicable perspectives to utilize physical information in the deep learning field and facilitates many data-intensive research endeavors.

8.
Adv Sci (Weinh) ; 11(34): e2309473, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38978348

RESUMO

Melatonin (N-acetyl-5-methoxytryptamine) is reported to improve mood disorders in perimenopausal women and gut microbiome composition is altered during menopausal period. The possible role of microbiome in the treatment effect of melatonin on menopausal depression remains unknown. Here, it is shown that melatonin treatment reverses the gut microbiota dysbiosis and depressive-like behaviors in ovariectomy (OVX) operated mice. This effect of melatonin is prevented by antibiotic cocktails (ABX) treatment. Transferring microbiota harvested from adolescent female mice to OVX-operated mice is sufficient to ameliorate depressive-like behaviors. Conversely, microbiota transplantation from OVX-operated mice or melatonin-treated OVX-operated mice to naïve recipient mice exhibits similar phenotypes to donors. The colonization of Alistipes Inops, which is abundant in OVX-operated mice, confers the recipient with depressive-like behaviors. Further investigation indicates that the expansion of Alistipes Inops induced by OVX leads to the degradation of intestinal tryptophan, which destroys systemic tryptophan availability. Melatonin supplementation restores systemic tryptophan metabolic disorders by suppressing the growth of Alistipes Inops, which ameliorates depressive-like behaviors. These results highlight the previously unrecognized role of Alistipes Inops in the modulation of OVX-induced behavioral disorders and suggest that the application of melatonin to inhibit Alistipes Inops may serve as a potential strategy for preventing menopausal depressive symptoms.


Assuntos
Comportamento Animal , Depressão , Modelos Animais de Doenças , Microbioma Gastrointestinal , Melatonina , Ovariectomia , Triptofano , Animais , Melatonina/farmacologia , Camundongos , Microbioma Gastrointestinal/efeitos dos fármacos , Triptofano/metabolismo , Triptofano/farmacologia , Feminino , Comportamento Animal/efeitos dos fármacos , Depressão/tratamento farmacológico , Depressão/metabolismo , Camundongos Endogâmicos C57BL , Disbiose/tratamento farmacológico
9.
Opt Lett ; 49(13): 3624-3627, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38950225

RESUMO

Slot-array antennas based on metallic waveguides have been widely used to generate pencil-beams, attracting attention due to their design simplicity and compact size. However, current slot-array antennas possess wavelength-scale profiles, which do not align optimally with the low-profile requisites of contemporary integrated communication and radar systems. Here, we propose a low-profile slot-array antenna designed specifically for the pencil-beam generation. Constructed with the two-dimensional-array (2D-array) slots situated on a sub-wavelength domino plasmon waveguide, the pencil-beam is generated with a peak gain of up to 21.6 dBi. Moreover, the generated pencil-beam allows for a wide scanning range of over 73.6° by adjusting the operating frequency from 45 to 65 GHz. Our research shows great potential for enhancing millimeter-wave radar capabilities and advancing communication systems.

10.
Front Biosci (Landmark Ed) ; 29(7): 245, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-39082333

RESUMO

BACKGROUND: Improving the clinical outcome of colorectal cancer (CRC) patients remains a major challenge. This study aimed to develop a new predictive classifier for CRC and to examine its relationship with the immune environment and therapeutic response. METHODS: A comprehensive bioinformatics analysis was applied to develop a risk panel comprised of cancer function status-related genes (CFSRGs). This panel was evaluated for prognostic utility by Area Under the Curve (AUC) and Kaplan-Meier (KM) analyses. Differences between high- and low-risk groups were subsequently investigated using multi-omics data. Immunohistochemistry (IHC), quantitative real-time polymerase chain reaction (qRT-PCR), and cell phenotype assays were also employed to ascertain the clinical value of STC2 expression. RESULTS: Significant differences were observed in the survival rate between high- and low-risk groups defined by our 7-CFSRG panel, both in internal and external CRC patient cohorts. The AUC for prediction of survival at 1-, 3- and 5-years was satisfactory in all cohorts. Detailed analysis revealed that tumor mutation burden, drug sensitivity, and pathological stage were closely associated with the risk score. Elevated expression of STC2 in CRC tissues relative to normal paraneoplastic tissues was associated with less favorable patient outcomes. qRT-PCR experiments confirmed that STC2 expression was significantly upregulated in several CRC cell lines (HCT116, SW480, and LOVO) compared to a normal intestinal epithelial cell line (NCM460). The proliferation, migration, and invasion of CRC cells were all significantly inhibited by knockdown of STC2. CONCLUSIONS: Our 7-CFSRG panel is a promising classifier for assessing the prognosis of CRC patients. Moreover, the targeting of STC2 may provide a novel therapeutic approach for improving patient outcomes.


Assuntos
Biomarcadores Tumorais , Neoplasias Colorretais , Humanos , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Neoplasias Colorretais/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Prognóstico , Feminino , Masculino , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Glicoproteínas/genética , Glicoproteínas/metabolismo , Idoso , Proliferação de Células/genética , Biologia Computacional/métodos
11.
BMC Pulm Med ; 24(1): 277, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862955

RESUMO

BACKGROUND: We aimed to determine whether systemic immune-inflammation index (SII) combined with prealbumin can provide better predictive power for postoperative pneumonia in patients undergoing lung resection surgery. METHODS: We identified eligible patients undergoing lung resection surgery at the Affiliated Hospital of Nantong University from March 2021 to March 2022. Demographic characteristics, clinical data, and laboratory information were collected and reviewed from the electronic medical records of the patients. To test the effect of the combined detection of SII and prealbumin, we made an equation using logistic regression analysis. The receiver operating characteristic curve (ROC) was plotted to evaluate the predictive powers, sensitivity, and specificity of prealbumin, SII, and SII combined with prealbumin. Decision curve analysis (DCA) was used to determine the clinical validity and net benefit of different methods of detection. RESULTS: Totally 386 eligible patients were included with a median age of 62.0 years (IQR: 55.0, 68.0), and 57 (14.8%) patients presented with postoperative pneumonia within 7 days after surgery. The multivariate regression analysis showed that preoperative SII as continuous variable was associated with an increased risk of postoperative pneumonia (OR: 1.38, 95% CI: 1.19-2.83, P = 0.011), whereas the prealbumin as continuous variable remained as an independent protective predictor of postoperative pneumonia in the adjusted analysis (OR: 0.80, 95% CI: 0.37-0.89, P = 0.023). Compared to SII or prealbumin, the combined detection of preoperative SII and prealbumin showed a higher predictive power with area under curve of 0.79 (95% CI: 0.71-0.86, P < 0.05 for all). Additionally, DCA indicated that the combined detection was superior over preoperative SII or prealbumin alone in clinical validity and net benefit. CONCLUSION: Both preoperative SII and prealbumin are independent influencing factors for postoperative pneumonia after lung resection surgery. The combined detection of preoperative SII and prealbumin can significantly improve prediction capability to identify potential postoperative pneumonia-susceptible patients, facilitating early interventions to improve postoperative quality of life for surgical lung resection patients.


Assuntos
Pneumonia , Complicações Pós-Operatórias , Pré-Albumina , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Pneumonia/diagnóstico , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Idoso , Pré-Albumina/análise , Pré-Albumina/metabolismo , Estudos Retrospectivos , Pneumonectomia/efeitos adversos , Valor Preditivo dos Testes , Curva ROC , Modelos Logísticos , Inflamação
12.
ACS Nano ; 18(26): 17065-17074, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38885193

RESUMO

Polaritons, hybrid light and matter waves, offer a platform for subwavelength on-chip light manipulation. Recent works on planar refraction and focusing of polaritons all rely on heterogeneous components with different refractive indices. A fundamental question, thus, arises whether it is possible to configure two-dimensional monolithic polariton lenses based on a single medium. Here, we design and fabricate a type of monolithic polariton lens by directly sculpting an individual hyperbolic van der Waals crystal. The in-plane polariton focusing through sculptured step-terraces is triggered by geometry-induced symmetry breaking of momentum matching in polariton refractions. We show that the monolithic polariton lenses can be robustly tuned by the rise of van der Waals terraces and their curvatures, achieving a subwavelength focusing resolution down to 10% of the free-space light wavelength. Fusing with transformation optics, monolithic polariton lenses with gradient effective refractive indices, such as Luneburg lenses and Maxwell's fisheye lenses, are expected by sculpting polaritonic structures with gradually varied depths. Our results bear potential in planar subwavelength lenses, integrated optical circuits, and photonic chips.

13.
Research (Wash D C) ; 7: 0375, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38826565

RESUMO

Pushing the information states' acquisition efficiency has been a long-held goal to reach the measurement precision limit inside scattering spaces. Recent studies have indicated that maximal information states can be attained through engineered modes; however, partial intrusion is generally required. While non-invasive designs have been substantially explored across diverse physical scenarios, the non-invasive acquisition of information states inside dynamic scattering spaces remains challenging due to the intractable non-unique mapping problem, particularly in the context of multi-target scenarios. Here, we establish the feasibility of non-invasive information states' acquisition experimentally for the first time by introducing a tandem-generated adversarial network framework inside dynamic scattering spaces. To illustrate the framework's efficacy, we demonstrate that efficient information states' acquisition for multi-target scenarios can achieve the Fisher information limit solely through the utilization of the external scattering matrix of the system. Our work provides insightful perspectives for precise measurements inside dynamic complex systems.

14.
Research (Wash D C) ; 7: 0367, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38694204

RESUMO

The flexible and conformal interconnects for electronic systems as a potential signal transmission device have great prospects in body-worn or wearable applications. High-efficiency wave propagation and conformal structure deformation around human body at radio communication are still confronted with huge challenges due to the lack of methods to control the wave propagation and achieve the deformable structure simultaneously. Here, inspired by the kirigami technology, a new paradigm to construct spoof plasmonic interconnects (SPIs) that support radiofrequency (RF) surface plasmonic transmission is proposed, together with high elasticity, strong robustness, and multifunction performance. Leveraging the strong field-confinement characteristic of spoof surface plasmons polaritons, the Type-I SPI opens its high-efficiency transmission band after stretching from a simply connected metallic surface. Meanwhile, the broadband transmission of the kirigami-based SPI exhibits strong robustness and excellent stability undergoing complex deformations, i.e., bending, twisting, and stretching. In addition, the prepared Type-II SPI consisting of 2 different subunit cells can achieve band-stop transmission characteristics, with its center frequency dynamically tunable by stretching the buckled structure. Experimental measurements verify the on-off switching performance in kirigami interconnects triggered by stretching. Overcoming the mechanical limitation of rigid structure with kirigami technology, the designer SPIs exhibit high stretchability through out-of-plane structure deformation. Such kirigami-based interconnects can improve the elastic functionality of wearable RF electronics and offer high compatibility to large body motion in future body network systems.

15.
Adv Mater ; 36(28): e2401738, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38771624

RESUMO

Metasurface holograms represent a common category of metasurface devices that utilize in-plane phase gradients to shape wavefronts, forming holographic images through the application of the generalized Snell's law (GSL). While conventional metasurfaces focus solely on phase gradients, metagratings, which incorporate higher-order wave diffraction, further expand the GSL's generality. Recent advances in certain acoustic metagratings demonstrate an updated GSL extension capable of reversing anomalous transmission and reflection, whose reversal is characterized by the parity of the number of wave propagation trips through the metagrating. However, the current extension of GSL remains limited to 1D metagratings, unable to access 2D holographic images in 3D spaces. Here, the GSL extension to 2D metagratings for manipulating waves within 3D spaces is investigated. Through this analysis, a series of acoustic metagrating holograms is experimentally demonstrated. These holographic images exhibit the unique ability to switch between transmission and reflection types independently. This study introduces an additional dimension to modern holography design and metasurface wavefront manipulation.

16.
Front Oncol ; 14: 1361603, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38800414

RESUMO

Bilateral breast cancer (BBC), an infrequent breast cancer subtype, has primarily been studied in terms of incidence, prognosis, and through comparative analysis of synchronous (SBBC) and metachronous (MBBC) manifestations. The advent and application of organoid technology hold profound implications for tumor research and clinical management. This study represents the pioneering use of organoid models in BBC research. We established organoid lines from two surgical tumor specimens of a BBC patient, with one line undergoing detailed pathological and genomic analysis. The BBC organoid from the right breast demonstrated a marker expression profile of ER (-), PR (-), HER-2 (0), and Ki67 index 10%, indicating that it may derived from the TNBC tissue. Whole Exome Sequencing (WES) displayed consistent set of Top10 cancer driver genes affected by missense mutations, frameshift mutation, or splice site mutations in three tumor tissues and the organoid samples. The organoids' single nucleotide polymorphisms (SNPs) were more closely aligned with the TNBC tissue than other tumor tissues. Evolutionary analysis suggested that different tumor regions might evolve from a common ancestral layer. In this case, the development of BBC organoids indicated that simultaneous lesions with diverse molecular profiles shared a high degree of consistency in key tumor-driving mutations. These findings suggest the feasibility of generating BBC organoids representing various molecular types, accurately replicating significant markers and driver mutations of the originating tumor. Consequently, organoids serve as a valuable in vitro model for exploring treatment strategies and elucidating the underlying mechanisms of BBC.

17.
Adv Mater ; 36(31): e2400797, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38801201

RESUMO

A crucial aspect in shielding a variety of advanced electronic devices from electromagnetic detection involves controlling the flow of electromagnetic waves, akin to invisibility cloaks. Decades ago, the exploration of transformation optics heralded the dawn of modern invisibility cloaks, which has stimulated immense interest across various physical scenarios. However, most prior research is simplified to low-dimensional and stationary hidden objects, limiting their practical applicability in a dynamically changing world. This study develops a 3D large-scale intelligent cloak capable of remaining undetectable even in non-stationary conditions. By employing thousand-level reconfigurable full-polarization metasurfaces, this work has achieved an exceptionally high degree of freedom in sculpting the scattering waves as desired. Serving as the core computational unit, a hybrid inverse design enables the cloaked vehicle to respond in real-time, with a rapid reaction time of just 70 ms. These experiments integrate the cloaked vehicle with a perception-decision-control-execution system and evaluate its performance under random static positions and dynamic travelling trajectories, achieving a background scattering matching degree of up to 93.3%. These findings establish a general paradigm for the next generation of intelligent meta-devices in real-world settings, potentially paving the way for an era of "Electromagnetic Internet of Things."

18.
Sci Bull (Beijing) ; 69(13): 2050-2058, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38782659

RESUMO

The Bloch band theory and Brillouin zone (BZ) that characterize wave-like behaviors in periodic mediums are two cornerstones of contemporary physics, ranging from condensed matter to topological physics. Recent theoretical breakthrough revealed that, under the projective symmetry algebra enforced by artificial gauge fields, the usual two-dimensional (2D) BZ (orientable Brillouin two-torus) can be fundamentally modified to a non-orientable Brillouin Klein bottle with radically distinct manifold topology. However, the physical consequence of artificial gauge fields on the more general three-dimensional (3D) BZ (orientable Brillouin three-torus) was so far missing. Here, we theoretically discovered and experimentally observed that the fundamental domain and topology of the usual 3D BZ can be reduced to a non-orientable Brillouin Klein space or an orientable Brillouin half-turn space in a 3D acoustic crystal with artificial gauge fields. We experimentally identify peculiar 3D momentum-space non-symmorphic screw rotation and glide reflection symmetries in the measured band structures. Moreover, we experimentally demonstrate a novel stacked weak Klein bottle insulator featuring a nonzero Z2 topological invariant and self-collimated topological surface states at two opposite surfaces related by a nonlocal twist, radically distinct from all previous 3D topological insulators. Our discovery not only fundamentally modifies the fundamental domain and topology of 3D BZ, but also opens the door towards a wealth of previously overlooked momentum-space multidimensional manifold topologies and novel gauge-symmetry-enriched topological physics and robust acoustic wave manipulations beyond the existing paradigms.

19.
Phys Rev Lett ; 132(15): 156602, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38682981

RESUMO

Photonic Chern insulators are known for their topological chiral edge states (CESs), whose absolute existence is determined by the bulk band topology, but concrete dispersion can be engineered to exhibit various properties. For example, the previous theory suggested that the edge dispersion can wind many times around the Brillouin zone to slow down light, which can potentially overcome fundamental limitations in conventional slow-light devices: narrow bandwidth and keen sensitivity to fabrication imperfection. Here, we report the first experimental demonstration of this idea, achieved by coupling CESs with resonance-induced nearly flat bands. We show that the backscattering-immune hybridized CESs are significantly slowed down over a relatively broad bandwidth. Our work thus paves an avenue to broadband topological slow-light devices.

20.
Sci Adv ; 10(16): eadn1746, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38640240

RESUMO

Phase modulation has scarcely been mentioned in diffusive physical systems because the diffusion process does not carry the momentum like waves. Recently, non-Hermitian physics provides a unique perspective for understanding diffusion and shows prospects in thermal phase regulation, exemplified by the discovery of anti-parity-time (APT) symmetry in diffusive systems. However, precise control of thermal phase remains elusive hitherto and can hardly be realized, due to the phase oscillations. Here we construct the PT-symmetric diffusive systems to achieve the complete suppression of thermal phase oscillation. The real coupling of diffusive fields is readily established through a strong convective background, and the decay-rate detuning is enabled by thermal metamaterial design. We observe the phase transition of PT symmetry breaking with the symmetry-determined amplitude and phase regulation of coupled temperature fields. Our work shows the existence of PT symmetry in dissipative energy exchanges and provides unique approaches for harnessing the mass transfer of particles, wave dynamics in strongly scattering systems, and thermal conduction.

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