Auxin-tolerant cotton (Gossypium hirsutum, L.) cultivars are the latest tools producers use to combat herbicide-resistant weed species during the growing season. The widespread implementation of auxin-tolerant crops has led to an increase in in-season applications of auxins. Auxin drift has subsequently become a more prominent issue in the agricultural industry and causes producers to shift management tactics. Yield partitioning research based on auxin application timing has been conducted, but more information is needed concerning application rate and the interaction between application rate and timing. Experiments were conducted from 2019 to 2021 in Grand Junction, TN, to determine the effects of synthetic auxin exposure on boll positioning, development, and production. Applications of 2,4-dichlorophenoxyacetic acid (2,4-D) or dicamba were made to cotton cultivars of the opposite technology at either matchhead square or 2 weeks after first bloom (FB + 2WK). Nontreated experimental plots were also included. More severe impacts on overall lint yield, yield partitioning, and yield components were observed following exposure to 2,4-D than dicamba. Application rate and timing also impacted yield components and partitioning. Exposure to 2,4-D during vegetative growth caused increased partitioning to vegetative and aborted fruiting positions but decreased partitioning to position 1, zone 2 (nodes 9 through 12), and zone 3 (nodes 13 and above) as application rate increased. Exposure to these rates at FB + 2WK did not impact yield partitioning. Environmental conditions following applications of 2,4-D or dicamba play an important role in the recovery and growth of cotton and subsequent yield penalties.

Heterostructures based on monolayer transition metal chalcogenide (TMD) semiconductors have offered a robust platform for exploring light‐matter interactions. The rotational misalignment between two TMDs enables modulation of the electronic band structure through the formation of an in‐plane moiré superlattice. Multiple interlayer excitons in TMD heterostructures have been reported under optical excitation, but studies related to optoelectronic devices remain limited. Here, electrically driven multiple interlayer excitons are demonstrated in the transient electroluminescence (EL) of MoSe 2 /WSe 2 heterostructures, sandwiched between two layers of hexagonal boron nitride (hBN) and a single graphene. The EL emission from multiple interlayer excitons in the MoSe 2 /WSe 2 heterostructures is induced by applying an alternating voltage to a two‐terminal device. The EL characteristic of interlayer excitons can be modulated by adjusting gate and pulse parameters, which control charge carrier injection into MoSe 2 /WSe 2 heterostructures. Furthermore, distinct recombination processes are reported in MoSe 2 /WSe 2 heterostructures with varying hole injection levels. The results provide a foundation for exploiting interlayer excitons in optoelectronic devices based on TMD heterostructures.

DLC films exhibit high hardness, low friction coefficient and chemical inertness but generally lack sufficient electrical conductivity. To achieve conductive films with substantial thickness, the combination of direct current plasma assisted chemical vapour deposition (DC PACVD) with high coating temperatures has proven to be effective. Nitrogen doping of DLC films, a common method for improving their electrical conduction properties, typically leads to enhanced graphitization and a reduction in hardness and Young's modulus in harder DLC coatings. This study examines how nitrogen doping affects the mechanical and electrical properties of already unusually conductive, soft and thick (> 25 mu m) a-C:H films deposited at elevated temperatures using pulsed direct current PACVD. The a-C:H:N films were grown using C2H2 at 450 degrees C and 550 degrees C with an addition of 0-63 vol.-% N2 to the gas phase and studied subsequently. Nitrogen modification of the a-C:H was highly effective at enhancing mechanical properties in conjunction with electrical conductivity. Hardness and Young's modulus increased by up to 48 % and 95 %, respectively, compared to the undoped films. Relative load bearing capacity improved by up to a factor of 3.7. Specific electrical resistance decreased by more than two orders of magnitude for films deposited at 450 degrees C and by a factor of four for deposition at 550 degrees C, approximating and even surpassing the conductivity of graphite electrodes. Conversely, film thickness and deposition rate decreased significantly due to etching effects compared to the undoped a-C:H.

Synthetic auxin herbicide movement onto sensitive cotton (Gossypium hirsutum L.) cultivars has impacted many US cotton hectares. The spatial scope and severity of auxin damage in-season is typically estimated by an agronomist. The use of remote sensing technology has the potential to objectively quantify the spatial scope and severity of auxin damage. Experiments were conducted in 2019, 2020, and 2021 in Grand Junction, TN, to determine: (1) the effect of reflectance data collection timing; (2) the effect of auxin exposure timing; (3) the value of near infrared and red-edge (RE) reflectance versus reflectance within the visible spectrum data; and (4) if/how visual injury relates to aerial reflectance data. Applications of 2,4-D or dicamba were made to susceptible cotton cultivars at 1X, 1/4X, 1/16X, 1/64X, 1/256X, and 1/1024X rates at either matchhead square (MHS) or 2 weeks after first bloom (FB+2WK). Non-treated controls were also included for each application timing. Aerial reflectance data were collected 7, 14, 21, and 28 days after application. Unsupervised classification of images into pixels with and without vegetation did not increase correlations between vegetation indices (VIs) and application rate. Although Vis, which generated the strongest correlations with application rate, visual injury, and relative lint yield, were generally RE based, similar correlations were also noted with visible spectrum VIs. Correlations were greater when auxin injury occurred at MHS than FB+2WK. Results suggest reflectance measured within the visible spectrum can quantify the scope and severity of auxin injury if the injury occurs early during the growing season. Remotely sensed reflectance has the potential to quantify the spatial scope and severity of synthetic auxin-injured cotton. Red-edge-based vegetation indices are most strongly correlated with application rate, visual injury, and lint yield. Similar correlations were noted with visible spectrum vegetation indices, application rate, visual injury, and lint yield. Greater correlation between injury and reflectance occurred at matchhead square than 2 weeks after first bloom. Visible spectrum reflectance can quantify the scope and severity of early-season auxin injury.

We experimentally demonstrate the first 1L-MoS2 microheater integrated with a silicon MRR, showing the best-reported power efficiency of ~7.5 mW/π with no significant penalty on insertion loss when placed close to the resonator (~30 nm).

Semiconductor quantum dots can generate single indistinguishable photons at telecom wavelengths for quantum networking applications. Integrating quantum dots into polarized microcavities is highly beneficial for advanced functionalities. In this work, we couple a quantum dot emitting in the telecom 'O' band to an elliptical bullseye resonator, demonstrating broadband polarization-selective enhancement and linearly polarized single-photon emission.

Efficient generation of entanglement between a stationary matter-qubit and a propagating photonic-qubit is a scientific and technological challenge of utmost importance for the realisation of fully-fledged quantum networks. Solid-state quantum emitters in the telecom C-band are a promising platform due to the minimal absorption of photons at these wavelengths and deterministic generation of high purity single photon flying qubits. Here, we use an InAs/InP quantum dot to implement an optically active spin-qubit and demonstrate high fidelity spin initialisation and coherent spin control of the resident electron. Lastly, for the first time we demonstrate high-fidelity spin-photon entanglement in a solid-state system with direct emission into the telecom C-band and obtain a lower bound on the entanglement fidelity of 80.07 %.

Transition metal dichalcogenides (TMDCs) are a promising class of two‐dimensional (2D) materials for flexible electronic applications due to their low integration temperature, good electronic properties, and excellent mechanical flexibility. Moreover, TMDCs offer the possibility of co‐integrating both n‐ and p‐type transistors on the same substrate, enabling the realization of complementary metal‐oxide‐semiconductor (CMOS) circuits. In this study, n‐type MoS2field‐effect transistors (FETs), and p‐type WSe2‐FETs integrated on a flexible foil substrate fabricated by standard thin‐film technology are presented. These devices exhibit high stability in their electronic operation under strain and repeated bending cycles. A CMOS inverter based on these transistors is also successfully demonstrated, which shows excellent switching behaviour with high gain (up to 100), high noise margin (0.87 · VDD), and low average static power consumption (40 pW).

MoS2 nanoswitches have shown superb ultralow switching energies without excessive leakage currents. However, the debate about the origin and volatility of electrical switching is unresolved due to the lack of adequate nanoimaging of devices in operando. Here, three optical techniques are combined to perform the first noninvasive in situ characterization of nanosized MoS2 devices. This study reveals volatile threshold resistive switching due to the intercalation of metallic atoms from electrodes directly between Mo and S atoms, without the assistance of sulfur vacancies. A "semi-memristive" effect driven by an organic adlayer adjacent to MoS2 is observed, which suggests that nonvolatility can be achieved by careful interface engineering. These findings provide a crucial understanding of nanoprocess in vertically biased MoS2 nanosheets, which opens new routes to conscious engineering and optimization of 2D electronics.

Thermal tuning of the optical refractive index in the waveguides to control light phase accumulation is essential in photonic integrated systems and applications. In silicon photonics, microheaters are mainly realized by metal wires or highly doped silicon lines placed at a safe distance (1um) from the waveguide to avoid considerable optical loss. However, this poses a significant limitation for heating efficiency because of the excessive free-carrier loss when a heater is brought closer to the optical path. In this work, we present a new concept of using optically transparent 2D semiconductors (e.g. MoS2) for realizing highly efficient waveguide integrated heaters operating at telecom wavelengths. We demonstrate that a single-layer MoS2 heater with negligible optical absorption in the infrared can be placed in close proximity (only 30nm) to the waveguide and show the best-reported heating efficiency of 15 mW per FSR without sacrificing the optical insertion loss. The heater response time is 25us, limited by Au 1L-MoS2 Schottky contact. Both the efficiency and response time can be further significantly improved by realizing 2D MoS2 heaters with ohmic contacts. Our work shows clear advantages of employing 2D semiconductors for heaters applications and paves the way for developing novel energy-efficient, lossless 2D heaters for on-chip photonic integrated circuits.

2D materials such as MoS2 remain one of the most important topics in materials industry [1]. MoS2 nanoswitches have shown superb ultralow switching energies [2] without excessive leakage currents [3]. However, the debate about the origin and volatility of electrical switching was unresolved due to the lack of adequate nanoimaging of devices in-operando [4].

Geometry, an ancient yet vibrant branch of mathematics, has important and far-reaching impacts on various disciplines such as art, science, and engineering. Here, we introduce an emerging concept dubbed "geometric deep optical sensing" that is based on a number of recent demonstrations in advanced optical sensing and imaging, in which a reconfigurable sensor (or an array thereof) can directly decipher the rich information of an unknown incident light beam, including its intensity, spectrum, polarization, spatial features, and possibly angular momentum. We present the physical, mathematical, and engineering foundations of this concept, with particular emphases on the roles of classical and quantum geometry and deep neural networks. Furthermore, we discuss the new opportunities that this emerging scheme can enable and the challenges associated with future developments.

Flexible electronics have been emerging in the last years for a wide variety of applications. In this scenario, transition metal dichalcogenides (TMDCs), such as molybdenum disulfide (MOS 2 ) and tungsten diselenide (WSe 2 ), have captured increased attention because of their complementary transport properties, and their excellent mechanical flexibility [1]. In particular, MOS 2 has shown good electron transport, while WSe 2 has predominantly shown hole transport [2]. This enables complementary metal-oxide semiconductor (CMOS) technology with its inherent advantages over its unipolar counterpart, i.e., low power dissipation and large noise immunity. Here, we demonstrate n-type MOS 2 and p-type WSe 2 field effect transistors (FETs) and combine them to form CMOS inverters on a flexible polyimide (PI) substrate.

Magnetic kagome metals, in which topologically non-trivial band structures and electronic correlation are intertwined, have recently emerged as an exciting platform to explore exotic correlated topological phases, that are usually not found in weakly interacting materials described within the semi-classical picture of electrons. Here, via a comprehensive single-crystal neutron diffraction and first-principles density functional theory study of the archetypical topological kagome metal Mn$_3$Sn, which is also a magnetic Weyl fermion material and a promising chiral magnet for antiferromagnetic spintronics, we report the realisation of an emergent spin-density wave (SDW) order, a hallmark correlated many-body phenomenon, that is engineered by the Fermi surface nesting of topological flat bands. We further reveal that the phase transition, from the well-known high-temperature coplanar and non-collinear k = 0 inverse triangular antiferromagnetic order to a double-$k$ non-coplanar modulated incommensurate magnetic structure below $T_1$ = 280 K, is primarily driven by the SDW instability. The double-$k$ nature of this complex low-temperature magnetic order, which can be regarded as an intriguing superposition of a longitudinal SDW with a modulation wavevector k$_L$ and a transverse incommensurate helical magnetic order with a modulation wavevector k$_T$, is unambiguously confirmed by our observation of the inter-modulation high-order harmonics of the type of 2k$_L$+k$_T$. This discovery not only solves a long-standing puzzle concerning the nature of the phase transition at $T_1$, but also provides an extraordinary example on the intrinsic engineering of correlated many-body phenomena in topological matter. The identified multi-$k$ magnetic state can be further exploited for the engineering of the new modes of magnetization and chirality switching in antiferromagnetic spintronics.

We report a comprehensive single-crystal neutron diffraction investigation of the Kitaev quantum magnet $\alpha$-RuCl$_{3}$ under hydrostatic pressure. Utilizing a He-gas pressure cell, we successfully applied an ideal hydrostatic pressure in situ at low temperatures, which allows to effectively eliminate any possible influences from the structural transition occurring between 200 K and 50 K under ambient conditions. Our experiments reveal a gradual suppression of the ziagzag antiferromagnetic order as hydrostatic pressure increases. Furthermore, a reversible pressure-induced structural transition occurs at a critical pressure of $P_d$ = 0.15 GPa at 30 K, as evidenced by the absence of magnetic order and non-uniform changes in lattice constants. The decrease in magnetic transition temperature is discussed in relation to a pressure-induced change in the trigonal distortion of the Ru-Cl octahedra in this compound. Our findings emphasize the significance of the trigonal distortion in Kitaev materials, and provide a new perspective on the role of hydrostatic pressures in the realization of the Kitaev quantum spin liquid state in $\alpha$-RuCl$_{3}$.

Optical spectroscopy is an indispensable technique in almost all areas of scientific research and industrial applications. After its acquisition, an optical spectrum is usually further processed using a mathematical algorithm to classify or quantify the measurement results. Here we present the design and realization of a smart photodetector that provides such information directly without the need to explicitly record a spectrum. This is achieved by tailoring the spectral responsivity of the device to a specific purpose. In-sensor computation is performed at the lowest possible level of the sensor system hierarchy - the physical level of photon detection - and does not require any external processing of the measurement data. The device can be programmed to cover different types of spectral regression or classification tasks. We present the analysis of spectral mixtures as an example, but the scheme can also be applied to any other algorithm that can be represented by a linear operator. Our prototype physical implementation utilizes an ensemble of optical cavity-enhanced MoS2 photodetectors with different center wavelengths and individually adjustable peak responsivities. This spectroscopy method represents a significant advance in miniaturized and energy-efficient optical sensing.

2-Dimensional (2D) materials are attracting strong interest in printed electronics because of their unique properties and easy processability, enabling the fabrication of devices with low cost and mass scalable methods such as inkjet printing. For the fabrication of fully printed devices, it is of fundamental importance to develop a printable dielectric ink, providing good insulation and the ability to withstand large electric fields. Hexagonal boron nitride (h-BN) is typically used as a dielectric in printed devices. However, the h-BN film thickness is usually above 1 μm, hence limiting the use of h-BN in low-voltage applications. Furthermore, the h-BN ink is composed of nanosheets with broad lateral size and thickness distributions, due to the use of liquid-phase exfoliation (LPE). In this work, we investigate anatase TiO2 nanosheets (TiO2-NS), produced by a mass scalable bottom-up approach. We formulate the TiO2-NS into a water-based and printable solvent and demonstrate the use of the material with sub-micron thickness in printed diodes and transistors, hence validating the strong potential of TiO2-NS as a dielectric for printed electronics.

The prevalence of potential human pathogenic members of the order Rickettsiales differs between Borrelia burgdorferi sensu lato-positive and -negative tick microbiomes. Here, co-infection of members of the order Rickettsiales, such as Rickettsia spp., Anaplasma phagocytophilum, Wolbachia pipientis, and Neoehrlichia mikurensis as well as B. burgdorferi s.l. in the tick microbiome was addressed. This study used conventional PCRs to investigate the diversity and prevalence of the before-mentioned bacteria in 760 nucleic acid extracts of I. ricinus ticks detached from humans, which were previously tested for B. burgdorferi s.l.. A gltA gene-based amplicon sequencing approach was performed to identify Rickettsia species. The prevalence of Rickettsia spp. (16.7%, n = 127) and W. pipientis (15.9%, n = 121) were similar, while A. phagocytophilum was found in 2.8% (n = 21) and N. mikurensis in 0.1% (n = 1) of all ticks. Co-infection of B. burgdorferi s. l. with Rickettsia spp. was most frequent. The gltA gene sequencing indicated that Rickettsia helvetica was the dominant Rickettsia species in tick microbiomes. Moreover, R, monacensis and R. raoultii were correlated with autumn and area south, respectively, and a negative B. burgdorferi s. l. finding. Almost every fifth tick carried DNA of at least two of the human pathogenic bacteria studied here.

Layered crystals are known to be good candidates for bulk thermoelectric applications as they open new ways to realise highly efficient devices. Two dimensional materials, isolated from layered materials, and their stacking into heterostructures have attracted intense research attention for nanoscale applications due to their high Seebeck coefficient and possibilities to engineer their thermoelectric properties. However, integration to thermoelectric devices is problematic due to their usually high thermal conductivities. Reporting on thermal transport studies between 150 and 300 K, we show that franckeite, a naturally occurring 2D heterostructure, exhibits a very low thermal conductivity which combined with its previously reported high Seebeck coefficient and electrical conductance make it a promising candidate for low dimensional thermoelectric applications. We find cross- and in-plane thermal conductivity values at room temperature of 0.70 and 0.88 W m(-1) K-1, respectively, which is one of the lowest values reported today for 2D-materials. Interestingly, a 1.77 nm thick layer of franckeite shows very low thermal conductivity similar to one of the most widely used thermoelectric material Bi2Te3 with the thickness of 10-20 nm. We show that this is due to the low Debye frequency of franckeite and scattering of phonon transport through van der Waals interface between different layers. This observation open new routes for high efficient ultra-thin thermoelectric applications.

In this study, we investigated the effect of periodic uniaxial strains on electron and phonon transports of poly-crystalline and single-crystal molybdenum disulphide (MoS 2 ) monolayers on a periodically corrugated sapphire surface. Analysis of micro-Raman, polarized photoluminescence and second harmonic generation results shows the anisotropy of the corrugation-induced strain in both single-and polycrystalline MoS 2 monolayers. AFM topography measurements show periodically-rippled surfaces of the MoS 2 in the nanometre scale. Our results show that the application of the periodic strain produces two major effects on the band structure of MoS 2 monolayers: modulations on the band gap anisotropy and reduction of out-of-plane spin-relaxation time due to substrate-induced bending of MoS 2 . Spin memory loss, in other words, shortening the spin relaxation time, enables an electron spin-flip scattering process that can convert a formerly bright exciton to a dark exciton. Such conversion is reflected in decreasing intensity of photoluminescence and in the light intensity collected by scanning near-field microscope. Our results demonstrate the ability to control both the bandgap and exciton character in monolayer MoS 2 via periodic strains imposed by corrugated sapphire substrates. This approach offers an effective means in designing novel electronic devices for photovoltaic applications. The bright-to-dark excitons conversion in photovoltaic devices can boast longer lifetimes than their bright exciton counterparts so they can be more efficiently collected by external electrodes. The strain-induced conversion of the bright-to-dark excitons makes the hybrid MoS 2 /corrugated sapphire structure an interesting platform for future photovoltaic applications.