All-electrical layer-spintronics in altermagnetic bilayers.

Electrical manipulation of spin-polarized current is highly desirable yet tremendously challenging in developing ultracompact spintronic device technology. Here we propose a scheme to realize the all-electrical manipulation of spin-polarized current in an altermagnetic bilayer. Such a bilayer system can host layer-spin locking, in which one layer hosts a spin-polarized current while the other layer hosts a current with opposite spin polarization.

Electrically Tunable and Modulated Perovskite Quantum Emitters via Surface-Enhanced Landau Damping.

Tuning quantum emission to a specific wavelength at room temperature holds significant promise for enhancing secure quantum communication, particularly by aligning with the Fraunhofer lines in the solar spectrum. The integration of quantum emitters with phase-change materials enables emission wavelength modulation, especially when strong field enhancement is present. Antimony telluride (SbTe) exhibits the potential to facilitate this functionality through its support of interband plasmonics and phase-change behavior.

Toward Phonon-Limited Transport in Two-Dimensional Transition Metal Dichalcogenides by Oxygen-Free Fabrication.

Developing future electronics will require aggressive scaling of the channel material thickness while maintaining device performance. Two-dimensional (2D) semiconductors are promising candidates to sustain further device scaling, but despite more than two decades of intense research, experimental performance continues to lag theoretical expectations. Here, we develop an oxygen-free approach to fabricate 2D field-effect transistors and push the electrical transport toward the theoretical phonon-limited intrinsic mobility.

Empowering nanophotonic applications via artificial intelligence: pathways, progress, and prospects.

Empowering nanophotonic devices via artificial intelligence (AI) has revolutionized both scientific research methodologies and engineering practices, addressing critical challenges in the design and optimization of complex systems. Traditional methods for developing nanophotonic devices are often constrained by the high dimensionality of design spaces and computational inefficiencies. This review highlights how AI-driven techniques provide transformative solutions by enabling the efficient exploration of vast design spaces, optimizing intricate parameter systems, and predicting the performance of advanced nanophotonic materials and devices with high accuracy.

Dynamic Tuning of Single-Photon Emission in Monolayer WSe via Localized Strain Engineering.

Two-dimensional (2D) materials have emerged as promising candidates for next-generation integrated single-photon emitters (SPEs). However, significant variability in the emission energies presents a major challenge in producing identical single photons from different 2D SPEs, which may become crucial for practical quantum applications. Although various approaches to dynamically tuning the emission energies of 2D SPEs have been developed to address the issue, the practical solution to matching multiple individual 2D SPEs is still scarce.

Universal conservation laws of the wave-particle-entanglement triad: theory and experiment.

When observed, a quantum system exhibits either wave-like or particle-like properties, depending on how it is measured. However, this duality is affected by the entanglement of the system with its quantum memory, raising a fundamental question: how are wave-particle duality and entanglement related? Here, we broaden the scope of wave-particle duality to include entanglement, introduce universal conservation laws for the wave-particle-entanglement triad, and perform demonstrations on silicon-integrated nanophotonic quantum chips. Our experiments not only mark the first confirmation of universal conservation laws but also highlight the potential of integrated photonics for exploring complex quantum phenomena in high-dimensional systems.

Achieving High Quality Factor Interband Nanoplasmonics in the Deep Ultraviolet Spectrum via Mode Hybridization.

Interband plasmons (IBPs) enable plasmonic behavior in nonmetallic materials, such as semiconductors. Originating from interband electronic transitions, IBPs are characterized by negative real permittivity that can extend into deep ultraviolet (DUV) spectrum, as demonstrated using silicon. However, the practical applications of IBPs are limited by their inherently broad resonances.

Pulsed vector atomic magnetometer using an alternating fast-rotating field.

We introduce a vector atomic magnetometer that employs a fast-rotating magnetic field applied to a pulsed Rb scalar atomic magnetometer. This approach enables simultaneous measurements of the total magnetic field and its two polar angles relative to the rotation plane. Operating in gradiometer mode, the magnetometer achieves a total field gradient sensitivity of 35 (0.

Infrared imaging with visible light in microfluidic devices: the water absorption barrier.

Infrared spectro-microscopy is a powerful technique for analysing chemical maps of cells and tissues for biomedical and clinical applications, yet the strong water absorption in the mid-infrared region is a challenge to overcome, as it overlaps with the spectral fingerprints of biological components. Microfluidic chips offer ultimate control over the water layer thickness and are increasingly used in infrared spectro-microscopy. However, the actual impact of the water layer thickness on the instrument's performance is often left to the experimentalist's intuition and the peculiarities of specific instruments.

Spectroscopic signatures and origin of hidden order in BaMgReO.

Clarifying the underlying mechanisms that govern ordering transitions in condensed matter systems is crucial for comprehending emergent properties and phenomena. While transitions are often classified as electronically driven or lattice-driven, we present a departure from this conventional picture in the case of the double perovskite BaMgReO. Leveraging resonant and non-resonant elastic x-ray scattering techniques, we unveil the simultaneous ordering of structural distortions and charge quadrupoles at a critical temperature of T ~ 33 K.

Mapping Guaranteed Positive Secret Key Rates for Continuous Variable Quantum Key Distribution.

The standard way to measure the performance of existing continuous variable quantum key distribution (CVQKD) protocols is by using the achievable secret key rate (SKR) with respect to one parameter while keeping all other parameters constant. However, this atomistic method requires many individual parameter analyses while overlooking the co-dependence of other parameters. In this work, a numerical tool is developed for comparing different CVQKD protocols while taking into account the simultaneous effects of multiple CVQKD parameters on the capability of protocols to produce positive SKRs.

Electrical Control of Valley Polarized Charged Exciton Species in Monolayer WS.

Excitons are key to the optoelectronic applications of van der Waals semiconductors, with the potential for versatile on-demand tuning of properties. Yet, their electrical manipulation remains challenging due to inherent charge neutrality and the additional loss channels induced by electrical doping. We demonstrate the dynamic electrical control of valley polarization in charged excitonic states of monolayer tungsten disulfide, achieving up to a 6-fold increase in the degree of circular polarization under off-resonant excitation.

Efficient photon-pair generation in layer-poled lithium niobate nanophotonic waveguides.

Integrated photon-pair sources are crucial for scalable photonic quantum systems. Thin-film lithium niobate is a promising platform for on-chip photon-pair generation through spontaneous parametric down-conversion (SPDC). However, the device implementation faces practical challenges.

Nonlinear dynamics of diamagnetically levitating resonators.

Unlabelled: The ultimate isolation offered by levitation provides new opportunities for studying fundamental science and realizing ultra-sensitive floating sensors. Among different levitation schemes, diamagnetic levitation is attractive because it allows stable levitation at room temperature without a continuous power supply. While the dynamics of diamagnetically levitating objects in the linear regime are well studied, their nonlinear dynamics have received little attention.

Estimation of Hamiltonian Parameters from Thermal States.

We upper bound and lower bound the optimal precision with which one can estimate an unknown Hamiltonian parameter via measurements of Gibbs thermal states with a known temperature. The bounds depend on the uncertainty in the Hamiltonian term that contains the parameter and on the term's degree of noncommutativity with the full Hamiltonian: higher uncertainty and commuting operators lead to better precision. We apply the bounds to show that there exist entangled thermal states such that the parameter can be estimated with an error that decreases faster than 1/sqrt[n], beating the standard quantum limit.

Realization of higher-order topological lattices on a quantum computer.

Programmable quantum simulators may one day outperform classical computers at certain tasks. But at present, the range of viable applications with noisy intermediate-scale quantum (NISQ) devices remains limited by gate errors and the number of high-quality qubits. Here, we develop an approach that places digital NISQ hardware as a versatile platform for simulating multi-dimensional condensed matter systems.