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When estimating the phase of a single mode, the quantum Fisher information for a pure probe state is proportional to the photon number variance of the probe state. In this work, we point out particular states that offer photon number distributions exhibiting a large variance, which would help to improve the local estimation precision. These theoretical examples are expected to stimulate the community to put more attention to those states that we found, and to work towards their experimental realization and usage in quantum metrology., 7 pages, 1 figure

Bonding TA1 and 304 stainless steel by explosive welding to obtain cladding plate. the microstructure of the bonded interface of the cladding plate was analyzed and its properties were tested. It was observed that the bonding interface of the cladding plate was periodically wavy. There is a large melting zone at the end of the interface waveform, and a vortex exists near the melting zone. The EDS surface scanning of the interface shows that there is element diffusion at the interface, and it is speculated that the bonding at the interface of the cladding plate belongs to metallurgical bonding. The microhardness measurement results show that the Vickers hardness (HV) at the interface is up to 413.10, and then the microhardness is lower with the distance from the interface junction, and gradually decreases to the same raw material. The tensile strength of 304 material after explosive welding reached 865MPa; the longitudinal shear strength of titanium-stainless steel cladding plate was 325MPa, and the transverse shear strength was 309MPa; The tested cladding plate has excellent corrosion resistance, and its corrosion resistance is between TA1 and 304. The self-corrosion current of the cladding plate is 233 μA.

One of the standard methods used to measure the size of nanoparticles in aqueous solutions in situ is dynamic light scattering (DLS). The principle of this technique used to measure the real size of nanoparticles in a solution is the use of a procedure that extrapolates the apparent diffusion coefficients at different scattering angles and the sample concentration to infinite conditions. The uncertainty in the measurement is related to the extrapolating procedure used, and we have evaluated this for nanoparticles with diameters in the range 20 nm to 100 nm using the methods described in the ISO Guide to the Expression of Uncertainty in Measurement. The size of nanoparticles measured using DLS was compared with that obtained using a microscopic method, a cryo-transmission electron microscope, to check the reliability of the results obtained from the DLS measurements, which showed good agreement within the uncertainty levels evaluated.

We have measured the heat flux accompanying the melting or freezing of metal (or metalloid)?carbon eutectics, using differential scanning calorimetry (DSC) to identify appropriate binary systems for secondary thermometry fixed points. Well-known alloy systems such as Fe?C and Ni?C showed reproducible endothermic and exothermic peaks that represent melting and freezing reactions in the DSC measurement. Furthermore, a new Si?C system with a eutectic composition showed reproducible melting and freezing peaks in the DSC measurements. Based on the results by DSC, we identified the Si?SiC eutectic point as a possible eutectic fixed point. To confirm this possibility, we made a Si?SiC cell for thermocouple thermometry and measured its melting and freezing characteristics using a Pt/Pd thermocouple. The melting temperature of the Si?SiC eutectic was reproducible to within 0.02??C (one standard deviation). From the results, we found that Si?SiC has possibility as a new eutectic fixed point at temperatures around 1400??C. We also concluded that DSC analysis could be used to measure the reproducibility of freezing and melting reactions that are to be used as fixed points for thermometry, because it is a rapid and easy-to-use tool for characterizing the thermal behaviour of materials with only a small sample.

Eutectic cells of Co/C and Ni/C for use in thermocouple calibration were manufactured and tested to investigate their melting and freezing characteristics using type B thermocouples. It was observed that the melting and freezing behaviour of Co/C and Ni/C systems are very similar. The freezing plateaus were found to be flatter than those of melting, but the melting points were closer to the ideal transition temperatures, which is an extrapolated value to zero temperature difference from the set temperature to induce melting/freezing, than the freezing points. Based on the observed results, the melting process is recommended for use when calibrating thermocouples.

We report the fabrication of branched β-Ga2O3 nanowires (NWs) by a post deposition-annealing process of host β-Ga2O3 NWs with Au catalyst seeds. The host β-Ga2O3 NWs grown by powder sputtering were decorated by Au thin films and then annealed at temperatures greater than 800 °C in vacuum, oxygen, and nitrogen atmospheres. No significant morphological changes were observed in the samples annealed under the oxygen atmosphere, while the dissociation of Ga2O3 into Ga and O species occurred in the samples annealed in vacuum and nitrogen atmosphere. In the case of annealing under the nitrogen atmosphere, however, branched β-Ga2O3 NWs were formed through a vapor–liquid–solid process with Au seeds, indicating that nitrogen atmosphere facilitates the supersaturation of Ga and O vapors into catalytic Au seeds. We observed that the photoluminescence peak intensity of branched NWs was increased by a factor of 20 compared with that of the host NWs. The peak position was also shifted from ∼500 to ∼640 nm.

InAlAs/InGaAs high electron mobility transistors (HEMTs) on an InP substrate with well-balanced cutoff frequency fT and maximum oscillation frequency fmax are reported. An InAlAs/InGaAs HEMT with 100-nm gate length and gate width of 2 × 50 μm shows excellent DC characteristics, including full channel current of 724 mA/mm, extrinsic maximum transconductance gm.max of 1051 mS/mm, and drain—gate breakdown voltage BVDG of 5.92 V. In addition, this device exhibits fT = 249 GHz and fmax = 415 GHz. These results were obtained by fabricating an asymmetrically recessed gate and minimizing the parasitic resistances. The specific Ohmic contact resistance was reduced to 0.031 OMmm. Moreover, the fT obtained in this work is the highest ever reported in 100-nm gate length InAlAs/InGaAs InP-based HEMTs. The outstanding gm.max fT, fmax, and good BVDG make the device suitable for applications in low noise amplifiers, power amplifiers, and high speed circuits.

We report the growth behavior of β-Ga2O3 nanowires (NWs) on sapphire (0001) substrates during radio-frequency magnetron sputtering. Upon fabrication, flat thin films grew initially, subsequent to which, NW bundles were formed on the surface of the thin film with increasing film thickness. This transition of the growth mode occurred only at temperatures greater than ~450 °C. The β-Ga2O3 NWs were grown through the self-catalytic vapor–liquid–solid mechanism with self-assembled Ga seeds. Secondary growth of NWs, which occurred from the sides of primary NWs resulting in branched NW structures, was also observed. Finally, the photoluminescence properties of as-grown and annealed β-Ga2O3 NW samples were investigated.

An apparatus for the evaluation of the figure of merit (ZT) of thermoelectric devices has been developed and ZT values have been estimated for a thermoelectric device. The most challenging problem in ZT value evaluation in this apparatus was measuring the thermal conductivity of the devices precisely. We have solved the problem by introducing a primary thermal conductivity measurement technique, a guarded hot plate method, which makes it possible to obtain directly and simultaneously four physical parameters related to the ZT, namely the thermal conductivity, electrical conductivity, Seebeck coefficient, and absolute temperature. The ZT evaluation was performed by a single scan of the temperature difference between the top and bottom surfaces of the device. We also addressed the thermoelectric properties and the power generation efficiency of a commercial thermoelectric device. The evaluation uncertainty of the ZT value was assessed to secure reliability of the apparatus and was found to be 3.59%.

The apparatus for evaluation of the figure of merit (ZT) of thermoelectric devices has been developed in order to investigate the performance of the thermoelectric devices. ZT value is comprised of three physical quantities, Seebeck coefficient, electrical conductivity, and thermal conductivity. In this study, we present new apparatus developed for evaluating the ZT and power generation efficiency of devices by direct measurement of thermal conductivity using guarded hot plate (GHP) method. The measured ZT values and power generation efficiency of the thermoelectric devices are presented.

The specific heat capacity of gallium nitride (GaN) was measured for polycrystalline powder and single crystal samples. We present the temperature dependence of the specific heat capacity for single crystal and powdered GaN from 100 to 1300 K. The difference between the polycrystalline powder and single crystal arises from thermal evaporation in the high-temperature region, and this depends on the degree of heat transfer at 100–200 K. The temperature dependence of the specific heat capacity in the form c p = 7.1380 ×10-17 T 6 - 2.9836 ×10-13 T 5 + 4.2185 ×10-10 T 4 - 1.5068 ×10-7 T 3 - 1.6713 ×10-4 T 2 + 0.1774T - 1.3545 (J mol-1 K-1) was derived from a least squares fitting routine.