Light–matter interaction involving magnetic resonance at optical frequencies has recently been extensively investigated for the development of optical metamaterials. Nevertheless, effective ...manipulation of magnetic dipole transitions at optical frequencies is rarely demonstrated. Herein is reported on an aerosol‐spray method for the gram‐scale production of all‐dielectric europium‐doped sub‐micrometer zirconia spheres, which support strong magnetic Mie resonances. In contrast to previous structures where magnetic dipole emitters are positioned outside dielectric nanoresonators, this structure offers an unprecedented opportunity for the light emitters to access the strong magnetic field within the dielectric nanoresonator. This unique architecture allows the magnetic emission from the doped europium ions to be effectively manipulated. Moreover, in gold nanosphere–europium‐doped zirconia sphere heterostructures, the electric dipole emissions of the europium ions are enhanced strongly by the plasmon resonance of the gold nanospheres, while the magnetic dipole emission is weakly affected, suggesting much weaker interaction between the magnetic dipole transition and the electric resonance. This work demonstrates the feasibility of using all‐dielectric nanoresonators for selectively manipulating the magnetic dipole emissions from embedded quantum emitters. In addition, this cost‐effective and productive synthesis method opens up many possibilities for the wide use of lanthanide‐doped dielectric nanoresonators in the field of nanophotonics.
All‐dielectric europium‐doped sub‐micrometer zirconia spheres are prepared by a cost‐effective and highly productive aerosol‐spray method. They support strong magnetic Mie resonances and offer an unprecedented opportunity for the light emitters to access the strong magnetic field within the dielectric nanoresonator. This unique architecture allows the magnetic emission from the doped europium ions to be effectively manipulated.
The mechanism of cancer metastasis remains poorly understood. Using gene profiling of hepatocellular carcinoma (HCC) tissues, we have identified GOLM1 as a leading gene relating to HCC metastasis. ...GOLM1 expression is correlated with early recurrence, metastasis, and poor survival of HCC patients. Both gain- and loss-of-function studies determine that GOLM1 acts as a key oncogene by promoting HCC growth and metastasis. It selectively interacts with epidermal growth factor receptor (EGFR) and serves as a specific cargo adaptor to assist EGFR/RTK anchoring on the trans-Golgi network (TGN) and recycling back to the plasma membrane, leading to prolonged activation of the downstream kinases. These findings reveal the functional role of GOLM1, a Golgi-related protein, in EGFR/RTK recycling and metastatic progression of HCC.
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•GOLM1 is identified as a leading gene relating to HCC metastasis•GOLM1 is correlated to early metastatic recurrence and poor survival of HCC patients•GOLM1 promotes growth and metastasis of HCC cells via activating EGFR/RTK•GOLM1 regulates recycling, spatial redistribution, and signaling kinetics of EGFR/RTK
Ye et al. identify GOLM1 as a key promoter of hepatocellular carcinoma (HCC) metastasis and determine its critical roles in the recycling, spatial redistribution, and signaling kinetics of EGFR/RTKs. In human HCC, GOLM1 expression is correlated with early recurrence, metastasis, and poor patient survival.
The two-dimensional (2D) superconducting state is a fragile state of matter susceptible to quantum phase fluctuations. Although superconductivity has been observed in ultrathin metal films down to a ...few layers, it is still not known whether a single layer of ordered metal atoms, which represents the ultimate 2D limit of a crystalline film, could be superconducting. Here we report scanning tunnelling microscopy measurements on single atomic layers of Pb and In grown epitaxially on Si(111) substrate, and demonstrate unambiguously that superconductivity does exist at such a 2D extreme. The film shows a superconducting transition temperature of 1.83 K for an atom areal density n=10.44 Pb atoms nm−2, 1.52 K for n=9.40 Pb atoms nm−2 and 3.18 K for n=9.40 In atoms nm−2, respectively. We confirm the occurrence of superconductivity by the presence of superconducting vortices under magnetic field. In situ angle-resolved photoemission spectroscopy measurements reveal that the observed superconductivity is due to the interplay between the Pb-Pb (In-In) metallic and the Pb-Si (In-Si) covalent bondings.
Directional light control at nanoscale shows great potential in applications such as holograms, optical neural networks, and ultracompact photonic circuits. Plasmonic nanostructures with designed ...geometrical shapes or complex architectures have been employed to manipulate light directionally. The interaction among the electric dipole and multipole resonances in plasmonic nanostructures enables the wavefront reshaping of light, leading to directional light scattering behaviors. However, traditional methods for directional light control suffer from complicated fabrication procedures and large footprints. In this work, heterodimers are constructed out of chemically grown Au nanodisks and Au nanorods, with the nanorod sitting vertically on the nanodisk, and their directional light scattering behaviors are studied. When the nanorod is located off the center of the nanodisk, the incident light is scattered asymmetrically by the heterodimer, producing a crescent‐shaped far‐field scattering pattern. The light scattering directionality of the heterodimers is further proved to be highly dependent on the aspect ratio of the nanorod, the relative position of the two nanocrystals, and the orientation of the nanorod. The study provides a solid and useful foundation for the directional light manipulation in ultracompact nanophotonic systems.
Unprecedented heterodimers are constructed out of silicon‐supported gold nanodisks and Au nanorods that are vertically oriented on the gold nanodisks. Such heterodimers exhibit asymmetric, crescent‐shaped far‐field scattering patterns. When the nanorod is located off the center of the nanodisk, the incident light will be scattered preferentially along the direction that is opposite to the nanorod.
At low temperature, collective excitations of one-dimensional (1D) interacting fermions exhibit spin-charge separation, a unique feature predicted by the Tomonaga-Luttinger liquid (TLL) theory, but a ...rigorous understanding remains challenging. Using the thermodynamic Bethe ansatz (TBA) formalism, we analytically derive universal properties of a 1D repulsive spin1 / 2 Fermi gas with arbitrary interaction strength. We show how spin-charge separation emerges from the exact TBA formalism, and how it is disrupted by the interplay between the two degrees of freedom that brings us beyond the TLL paradigm. Based on the exact low-lying excitation spectra, we further evaluate the spin and charge dynamical structure factors (DSFs). The peaks of the DSFs exhibit distinguishable propagating velocities of spin and charge as functions of interaction strength, which can be observed by Bragg spectroscopy with ultracold atoms.
Dynamic and topological phenomena correspond to many new characteristics of matter and have broad application prospects. Focusing on the one-dimensional spin system, different types of topological ...phases are detected from the viewpoint of non-equilibrium dynamics. The concept of single-site excitation quantum quench is introduced considering the characteristic topological edge state of a topological phase to investigate topological phases. Owing to the protection of edge states against boundary disturbances for a topologically non-trivial phase, the rate function of the Loschmidt echo under quantum quench shows quite different dynamic behaviours during application of single-site excitation on the boundary and interior sites, while no such difference is observed for a topologically trivial phase. This phenomenon also exists on the time-evolved order parameters. The method discussed in this work provides a deep understanding regarding topological protection and a new way to characterise topological phases from the dynamical viewpoints.
•New dynamical methods in detecting topological quantum phases are proposed.•Topologically protected edge states are also testified by time-evolved order parameters.•The superior applicability and consequence of these dynamical methods are analyzed in detail.•Conclusions about the relationship between topology and structures in the previous literature are verified.
To explore carbide superconductors with higher transition temperature, two novel carbon structures of cage‐network are designed and their superconductivity is studied by doping metals. MC6 and MC10 ...are respectively identified as C24 and C32 cage‐network structures. This study finds that both carbon structures drive strong electron–phonon interaction and can exhibit superconductivity above liquid nitrogen temperature. Importantly, the superconducting transition temperatures above 100 K are predicted to be achieved in C24‐cage‐network systems doped by Na, Mg, Al, In, and Tl at ambient pressure, which is far higher than those in graphite, fullerene, and other carbides. Meanwhile, the superconductivity of cage‐network carbides is also found to be sensitive to the electronegativity and concentration of dopant M. The result indicates that the higher transition temperatures can be obtained by optimizing the carbon‐cage‐network structures and the doping conditions. The study suggests that the carbon‐cage‐network structure is a direction to explore high‐temperature superconducting carbides.
The novel carbon structures of cage‐network is designed. The superconducting transition temperature above 100 K are predicted to be achieved in C24‐cage‐network systems doped by metals at ambient pressure, which is far higher than those in graphite, fullerene, and other carbides. The study suggests that the carbon‐cage‐network structure is a direction to explore high‐temperature superconducting carbides.
We perform a systematic quantum Monte Carlo study of the pairing correlation in the S(4) symmetric microscopic model for iron-based superconductors. It is found that the pairing with an extensive ...s-wave symmetry robustly dominates over other pairings at low temperature in a reasonable parameter region regardless of the change of Fermi surface topologies. The pairing susceptibility, the effective pairing interaction, and the (π, 0) antiferromagnetic correlation strongly increase as the on-site Coulomb interaction increases, indicating the importance of the effect of electron-electron correlation. Our nonbiased numerical results provide a unified understanding of the superconducting mechanism in iron pnictides and iron chalcogenides and demonstrate that the superconductivity is driven by strong electron-electron correlation effects.
Further increasing the critical temperature and/or decreasing the stabilized pressure are the general hopes for the hydride superconductors. Inspired by the low stabilized pressure associated with Ce ...4f electrons in superconducting cerium superhydride and the high critical temperature in yttrium superhydride, we carry out seven independent runs to synthesize yttrium-cerium alloy hydrides. The synthetic process is examined by the Raman scattering and X-ray diffraction measurements. The superconductivity is obtained from the observed zero-resistance state with the detected onset critical temperatures in the range of 97-141 K. The upper critical field towards 0 K at pressure of 124 GPa is determined to be between 56 and 78 T by extrapolation of the results of the electrical transport measurements at applied magnetic fields. The analysis of the structural data and theoretical calculations suggest that the phase of Y
Ce
H
in hexagonal structure with the space group of P6
/mmc is stable in the studied pressure range. These results indicate that alloying superhydrides indeed can maintain relatively high critical temperature at relatively modest pressures accessible by laboratory conditions.
Understanding how symmetries encode optical polarization information into selection rules in molecules and materials is important for their optoelectronic applications including spectroscopic ...analysis, display technology, and quantum computation. Here, we extend polarization-dependent selection rules from atoms to solid-state systems with various point groups with the help of the rotational operator for circular polarization and the twofold rotational operator (or reflection operator) for linear polarization. We use these new selection rules to study the optical properties of twisted bilayer graphene quantum dots (TBGQDs), which inherit advantages of graphene quantum dot including its ultrathin thickness, excellent biocompatibility, and shape- and size-tunable optical absorption or emission. We study how the electronic structures and optical properties of TBGQDs rely on size, shape, twist angle, and correlation effects for TBGQDs with 10 different point groups for which we obtain an optical selection rule database. We show how current operator matrix elements identify the generalized polarization-dependent selection rules. Our results show that both the electronic and optical band gaps follow power-law size scalings with a dominant role of the twist angle. We derive an atlas of optical conductivity spectra for both size and twist angle in TBGQDs. As a result of quantum confinement effects, in the atlas a new type of optical conductivity features emerges with multiple discrete absorption frequencies ranging from infrared to ultraviolet energy, allowing for applications in photovoltaic devices and photodetectors. The atlas and size scaling provide a full structure–symmetry-function interrelation and hence offer an excellent basis for the geometrical manipulation of optical properties of TBGQDs as building blocks for novel integrated carbon optoelectronics.
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